© 2004 by European Society of Cardiology
Abstracts
| 4-1 PULMONARY VEIN ISOLATION USING ULTRASOUND BALLOON ABLATION FOR TREATMENT ATRIAL FIBRILLATION WITHOUT RISK OF PULMONARY VEIN STENOSIS Ma CS, Liu XP, Dong JZ, Liu X, Wang JA, Fang DP, Liu XQ, Wang J. Department of Cardiology, Beijing Anzhen Hospital, Beijing 100029, P. R. China Objective: Pulmonary vein (PV) stenosis following radiofrequency catheter ablation (RFCA) for curing atrial fibrillation is a serious complication (incidence from 1% to 10%). The impact of different ablation energy on the incidence of PV stenosis has not been well described. Aim of the study was to determine the long-term safety and efficacy of anatomical PV isolation with an ultrasound balloon ablation system (IBI Inc.). Methods: Circumferential ultrasound balloon ablation of both upper PVs and left inferior PV were performed in 47 patients (mean age 55±10 years; 38 males) with symptomatic and drug refractory paroxysmal atrial fibrillation. The procedural endpoint was PVs isolation. A contrast-enhanced magnetic resonance angiography (MRA) of PVs were performed before, at 1 week and 6 months after the ablation procedure to define the anatomy of PVs and to measure the diameter of ostium of each PVs in all patients. Results: Of 137 PVs targeted, 101 (73.7%) were successfully isolated. After a mean period of 18.8±9.2 (8{small tilde}30) months of follow-up, atrial fibrillation was completely eliminated in 19 patients (40.4%) without antiarrhythmic drug. There was no acute PV stenosis or thrombosis observed in any treated PVs based on the venogram performed during the procedure. At 1 week and 6 months after the procedure, the MRA of PVs showed no evidence of stenosis or even mild narrow (<25% diameter) in any patients. Conclusions: Ultrasound balloon ablation can isolate PV with an acceptable efficacy profile and without PV stenosis. Key word Atrial fibrillation Ablation Pulmonary vein stenosis
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| 4-2 PREDICTORS OF CONVERSION TO SINUS RHYTHM DURING CATHETER ABLATION OF PERSISTENT ATRIAL FIBRILLATION McElderry HT, Lan DZ, Epstein AE, Plumb VJ, Kay GN. University of Alabama at Birmingham. In some patients with persistent AF, catheter ablation encircling the pulmonary veins (PVs) restores sinus rhythm (SR) without requiring cardioversion (CV). In this study we characterized features of the ECG and intracardiac electrograms that predicted conversion to SR during ablation. Methods: 33 pts (male 20, mean age 55yrs) with persistent AF referred for catheter ablation were studied. AF waves were defined as coarse in an ECG lead if the mean amplitude was >0.1 mV. If <0.1 mV, then AF was defined as fine. Intracardiac electrograms in the coronary sinus (CS) were defined as organized if there was a repeating pattern of activation with discrete isoelectric segments. Patients were divided into two groups based on whether AF terminated during ablation: In Grp A (15 pts), SR was restored, and in Grp B (18 pts) AF persisted after encircling all 4 PVs. Results: AF was coarse in more ECG leads in Grp A than B (9.4+6.5 vs. 3.8+6.5, P<0.001). If AF was coarse in >10 leads, all pts converted to SR (9/9); if AF was coarse in <6 leads, 13 of 14 pts required CV. In lead II, the average fibrillation wave amplitude was 0.19+0.04mV in Grp A and 0.09+0.02mV in Grp B (P<0.001). The mean CL in the CS was longer in Grp A than B (209.8+694ms vs. 169+792ms, p=0.007) and the CS activation pattern was organized in 10/15 pts in Grp A vs. 5/18 pts in Grp B (p=0.057). The CS electrograms included an isoelectric segment in 11/15 pts in Grp A and 5/18 pts in Grp B (p=0.24). Conclusions: Patients with persistent AF that converts to SR during ablation have more coarse AF, a more organized CS activation pattern, and discrete isoelectric intervals. These findings suggest a longer wavelength and fewer atrial wavefronts in these patients.
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| 4-3 NEW INSIGHTS INTO ELECTRICAL CONNECTIONS BETWEEN PULMONARY VEINS DEMONSTRATED BY EXTENSIVE ENCIRCLING ISOLATION OF IPSILATERAL PULMONARY VEINS Y. Nagata, M. Goya, K. Suzuki, Y. Takahashi, A. Takahashi, Y. Iesaka, Tsuchiura Kyodo Hospital, Japan Electrical connections between contiguous pulmonary veins (PVs) (inter-PV connections) might be a cause of difficult PV isolation in patients with paroxysmal atrial fibrillation (AF). To avoid complexity and risk of PV narrowing, we developed a new method of extensive encircling isolation of ipsilateral PVs (EEI), guided by simultaneous recordings from 2 decapolar circular catheters placed in both the ipsilateral upper and lower PVs. We assessed the prevalence of inter-PV connections during EEI. Methods: Sixty-seven consecutive patients with paroxysmal or persistent AF (57 males, 53±10 years) underwent EEI. Radiofrequency (RF) energy was administrated in the junction between left atrium (LA) and PVs. The septum wall between the contiguous PVs was excluded from RF delivery. After isolation of ipsilateral PVs, intra-PV pacing was performed. Results: In 45/133 pairs of successfully isolated ipsilateral PVs (left 23/67; 34% and right 22/66; 33%), contiguous PVs were disconnected simultaneously by final RF delivery (indirect evidence of inter-PV connections). Direct evidence of inter-PV connections were demonstrated by follows; 1) intra-PV pacing associated with contiguous PVs capturing was shown in 17 left and 12 right ipsilateral PVs, 2) dissociated PV spikes encompassing upper and lower PVs emerged spontaneously in additional 2 left and 3 right ipsilateral PVs. Conclusions: Inter-PV connections were estimated from indirect and direct evidence to be present nearly in 30% of paired PVs. EEI using simultaneous monitoring of ipsilateral PVs makes the detailed anatomy of the connection between LA and PVs clear, and can conquer the complexity and risk in PV disconnection.
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| 4-4 SIGNALS RECORDED AT OSTIA OF THE PULMONARY VEINS CAN BE CLEARLY DISCRIMINATED BY DIFFERENT-SITE PACING AND ABLATION IN PATIENTS WITH PAROXYSMAL ATRIAL FIBRILLATION Jian Chen, Per Ivar Hoff, Knut Ståle Erga, Ole-Jørgen Ohm, MD, PhD. Haukeland University Hospital, Bergen, Norway Introduction: The pulmonary vein (PV) isolation has been used to treat patients with paroxysmal atrial fibrillation (PAF). It may be difficult to differentiate PV potentials from atrial signals. We sought to interpret the recordings made in the PVs during ablation and by different-site pacing. Methods and results: This study consisted of 63 consecutive patients with PAF (50 men, 13 women, mean age 53± 11). The numbers of the PVs studied are listed in the table. 20 PVs were excluded from the study because ablation was performed during PAF. A Lasso catheter was positioned in the ostia of the PVs for recording. A multi-electrode catheter and another ablation catheter were positioned in the coronary sinus (CS) and left atrial appendage (LAA) respectively for pacing. Another 4-polar electrode was placed in between the right atrium and the superior vena cava (SVC) for recording and pacing. There were two types of signals recorded at the ostia of the PVs: double potentials or one fractional potential in the left PVs (during CS pacing) and the right PVs (in sinus rhythm). The timing of the first signal of double potentials was the same as that of the potential recorded in LAA (for the left PVs) or in the SVC (for the right PVs) either during LAA/ SVC pacing or in sinus rhythm. The second potential was delayed in some patients and abolished in all patients by PV ostimn ablation.
Conclusions: The recordings at the ostia of the PVs consist of the PV potentials, the far-field potentials of the LAA (the left PVs) or SVC (the right PVs) and the local atrial potentials. The relations and intervals of these potentials could be revealed by pacing in the LAA or in the SVC.
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| 4-5 DIFFERENTIAL SITE ATRIAL PACING TO IDENTIFY PULMONARY VEIN POTENTIALS Richard Klein, Univ of Utah and VA Medical Center, Salt Lake City, UT Craig Swygman, Boston Scientific, San Jose, CA Identification of pulmonary vein potentials (PVP) is critical to identifing myocardial segments in PVs for PV isolation as therapy for atrial fibrillation (AF). Because this can be difficult during sinus rhythm pacing from different atrial sites might improve PVP identification. Methods: During ablation for PV isolation, pacing and premature stimulation (PES) were performed from the distal coronary sinus (CS), posterior left atrium (LA), LA appendage (A) and right atrium (RA). PVs were mapped with a basket catheter positioned at the PV orifice. In 14 pt a total of 43 PVs could be mapped and the pacing protocol completed. Results: Pacing and PES from the posterior LA most consistently separated PVPs in both right and left PVs.Distal CS pacing was not consistent in separating PVPs, possibly due to variations in CS-LA electrical connections. Pacing from the RA was least useful in identifying PVPs in both right and left PVs; PVPs were not separated with RA pacing in any of the left PVs. Programmed PES at all sites was more effective in separating LA and PV potentials than atrial pacing; decremental PES always resulted inprolongation of local LA-PVP timing. In selected pts, pacing from the interatrial septum was helpful in differentiating local atrial potentials from PVPs in the right inferior PV. Conclusion: Pacing from different left atrial sites can be useful in differentiating local atrial potentials from true PVPs during ablation for PV isolation. The most effective site was the posterior LA; premature stimulation was more effective in separating PVPs from local atrial potentials.
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| 4-6 INDIVIDUALIZED AF ABLATION AS GUIDED BY NON INDUCIBILITY P. Jaïs Different strategies have been reported for ablation of paroxysmal AF (PAF), using pulmonary vein isolation (PVI) ± left atrial (LA) linear lesions but none have been individually tailored. Methods 46 Patients (7 F, 53±10 yrs) undergoing ablation of PAF (7±7 yrs) were studied with the end point of non inducibility (NI). PVI and cavotricuspid ablation were first performed while further linear ablation was guided by the inducibility of AF. Sequential linear lesions (either at mitral isthmus or LA roof or both) were performed up to achieving NI of AF or flutter. Inducibility was assessed by pacing (20 mA) at maximum rate allowing 1:1 atrial capture from both appendages and coronary sinus. Results Before ablation, AF was present spontaneously in 13 pts (35%). 24 pts underwent only PVI and cavotrivuspid ablation as AF was rendered NI. Linear ablation was required in 22 pts (48%). In 17, a single linear lesion was performed for inducible AF (16) or peri right veins flutter (1) involving mitral isthmus in 12 or LA roof in 5. Linear block was achieved in all and resulted in NI. In 5 pts, persisting inducibility (2) or fibrillation (3) after the initial linear lesion required a second linear lesion resulting in linear block in 4/5 roof and 3/5 mitral isthmus. After the second linear lesion, AF and left flutter were still inducible in 1 each. At the end of this staged approach, NI was achieved in 44/46 (96%). Early reablation was performed in 10/46 (22%) for PV recurrence (5), non PV foci (3) and peri mitral flutter (2). With a follow-up of 6±5 months, 42/46 (91%) pts were free of AF without antiarrhythmic drugs. Conclusion An individually tailored approach aiming to achieve NI results in successful ablation in 91% of PAF: ablation target were limited to PVI in 52% of the patients, and required additional linear lesions in the remaining.
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| 9-1 ICD LEADS. HOW OFTEN DO THEY FAIL AT LONG TERM? TN MAOUNIS, G POULOS, E EVGENIADOU, K KATSAROS, AS MANOLIS, DV COKKINOS, 1st Dpt of Card, Onassis Cardiac Surg Ctr, Athens, Greece The implanted defibrillator leads (IDL) are complex leads used both for pacing and sensing the ventricle and for defibrillation. The purpose of this study is to evaluate the long term performance of IDL. The long term performance of the IDL was evaluated in 69 patients (pts) who had defibrillators implanted in our institution, who had a regular follow-up for at least 36 months and in whom the performance of the IDL was normal during this initial period. The underlying heart disease was coronary artery disease in 52, dilated cardiomyopathy in 6, hypertrophic cardiomyopathy in 4, and other diseases in 7. Mean age of the pts was 63+14 years and mean ejection fraction 35+9%. There were 62 men and 7 women. Mean follow-up was 68+23 months. During this extended follow-up in 60 pts the IDL continued to function normally. In 9 pts (13%) lead related problems were encountered. In two pts oversensing due to lead fracture was noted resulting in inappropriate shocks. In two other pts oversensing occurred only after defibrillator shock. In one pt high pacing threshold, low pacing impedance and low defibrillation impedance developed 34 months after implantation. In one pt exteriorization of the lead occurred 36 months after implantation. In 1 pt high defibrillation threshold and oversensing after the shock was found at replacement. Finally 2pts had a unipolar ventricular pacing and sensing IDL which was not compatible with the generators available at replacement. In a significant number of pts despite a normal IDL performance during the first two years after implantation lead related problems can occur at extended follow up. Regular tests are essential in order to ensure the proper function of the implanted defibrillator and the safety of the pts.
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| 9-2 Incidence, Timing, and Management of ICD Lead Failure. Frauke Gorré, Heidi Rottiers, Winoc Fonteyne MD, Mattias Duytschaever MD, PhD, and Rene Tavernier, MD, PhD, Department of Cardiology, University Hospital Ghent, Belgium. Background. Data on long term ICD lead survival are scanty. Aims. To asses the incidence, timing, presentation and management of failure of the Medtronic 6936/6966 defibrillator leads (both coaxial, non steroid-eluting, polyurethane insulated screw-in leads, only differing in connector type). Methods. Between July 1991 and November 1998, 164 leads (31 Medtronic 6966 and 133 Medtronic 6936) were implanted in 155 patients and followed by ICD interrogation every 3 months (mths). Results. After a mean follow-up of 63±37 mths, 24 leads were abandoned (19 electrical failures after 72±27 mths and 5 infections after 38±25 mths, p< 0,05). In contrast to infections which occur early after implantation, electrical failure probability increases significantly after 80 mths and reaches 30% after 120 mths. Electrical failure presented as oversensing in 14 pts resulting in inappropriate shock delivery in 9 and syncope in one patient due to inappropriate pacing inhibition after hisbundle ablation. A pacing impedance > 2000 Ohms suggesting lead fracture was observed in 3 cases and a high pacing threshold making antitacliycardia pacing impossible in 2 cases. The defect electrode was extracted in 11 cases, capped in 7 and repaired with silicone in 1 case. All infected leads were explanted.
Conclusions: Inappropriate shock delivery is the most frequent presentation of electrical lead dysfunction. In the long-term (>5yrs) reliability of ICD leads is limited.
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| 9-3 VERY LATE FOLLOW-UP OF ACCUFIX 801 ATRIAL LEADS David L. Hayes, MD, David R. Holmes, MD and Linda K. Hyberger. Mayo Clinic, Rochester, MN. Accufix 801 lead follow-up will remain a concern as long as leads are in place. There were 301 Accufix 801 leads that were either implanted or followed at our institution. 120 leads have been removed over the experience. Of the remaining 181 pts, 103 of the pts have expired. No deaths can be attributed to 801 lead failure. Of 78 remaining pts, 43 pts have been lost to follow-up leaving 35 pts who are still actively followed. The most recent fluoroscopic screening offered was 11/5/03. Of the 35 pts screened, there were 2 previously identified fractures with retention wire separation but no definite protrusion from the insulation and unchanged from prior screening. From 1/97 to 11/03, an additional twenty-two 801 leads have been removed from service. Of these, 6 have been abandoned and capped but are still in place and undergo regular surveillance and an additional 16 pts have had the lead extracted. Reasons for extraction were: elective-4, fracture-7, heart transplant-1, infection-2, lead malfunction-1, and removal during tricuspid valve replacement-1. Of the 7 fractured leads; 3 had retention wire separation without insulation protrusion; in 2 pts there were fractures but it could not be determined whether the retention wire was extruding through the insulation; and in 2 pts there was definite extrusion through the insulation. The latest fracture detection occurred at 141 months post implant and 14 months since the last fluoroscopic screening. Summary: Although a relatively small number of our original Accufix population is still being followed with Accufix leads in place (11.6%), fractures are still being identified. Given the potential risk for 801 retention wire fracture even as late as 141 mos post-implant, fluoroscopic surveilance should be continued.
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| 9-4 VENTRICULAR LEAD MODEL CHARACTERISTICS OVER TIME: KAPPA 900® REGISTRY J. Benezet1, W. Landgraf2, K. Kubisch2, A. Cuijpers3, B. Huegl4, S. Henschke5, for the Kappa 900 Registry investigators. Hospital N.S. de Alarcos, Ciudad Real1, Cardiology Clinic, Dortmund2, Bakken Research Center, Maastricht3, Hospital Bad Berka4, KKH Martha-Maria, Halle Dölau5. Purpose: The Medtronic (MDT) Kappa 900 (K900) Pacemaker (PM) Lead Trend diagnostics was used to describe and compare the characteristics of implanted ventricular (V) leads. Methods: Over a 1.8 year period, 95 investigators collected K900 device data from 1595 PM patients suffering from syncope and dizzy spells (54% males, 70±15 years, 66% SND, 80% dual chamber PM, 30% PM dependent). Chronic Pacing Threshold (PT), Auto-Sensitivity (SE) and Impedance (Im) Trend data from 109 different V-leads were retrospectively analyzed, V-leads were grouped into 7 families: 5 MDT endocardial (MDT), 1 MDT epicardial (MDT-Epi) and 1 non-MDT. Results: The table below summarizes the results
Conclusion: K900 Trend Data accurately track properties of leads. Intra-lead pace/sense properties are stable over time.
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| 9-5 LEFT VENTRICULAR LEAD PERFORMANCE IN 120 CONSECUTIVE PATIENTS Andi Eie Albertsen, Jens Cosedis Nielsen, Anders Kirstein Pedersen, Peter Steen Hansen, Henrik Kjærulf Jensen, Peter Thomas Mortensen-Aarhus, DNK OBJECTIVES: Evaluate left ventricular (LV) lead performance and pacemaker related complications in patients treated with Bi-Ventricular pacing. The tip of the LV lead is placed in a coronary sinus tributary. METHODS AND RESULTS: LV lead implant was successful in all of 120 attempted cases (94 male, mean age 62 years, 52% ischaemic heart disease). Implantation and fluoroscope times were reduced in the period from 190 min. to 80 min. and 44 min. to 22 min respectively. Mean follow up was 16.7 months. LV leads thresholds raised during the first month and stabilized afterwards. Reoperation was done in 12 patients because of loss of LV lead capture (6 ptt.), phrenic nerve pacing (3ptt.) and infection (3 ptt.). Another 8 patients had phrenic nerve stimulation at thresholds from 0.75 to 5 V at 0,5 ms duration all treated with pacemaker reprogramming. Two cases of coronary sinus dissection occurred and were treated conservatively. CONCLUSION: Implantation of a pacemaker electrode in a coronary sinus tributary is feasible and safe. Left ventricular lead performance is stable during the first 18 months of follow-up.
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| 9-6 ANOTHER MEASURE OF LEAD RELIABILITY GFO Tvers RG Hauser M Gao J Clark Multi-Center Minneapolis Heart Institute and B.C. Cardiac Registries Vancouver. Purpose Since 1999 the MHIR has independently gathered lead (L) and pulse generator (PG) failure (F) data from 19 centers. All PGs will eventually fail due to EOL so L F should be <PG F; and, as many L models show
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1% F up to 20yrs but others show 
5% F by Syrs, we evaluated L to PG F ratios as a potential measure of L reliability. Method L/PG F ratios were calculated for all MHIR data and for the 3 companies (CO) with 85% of PG reports. Risk ratio (RR) calculations assume random PG Fs and overall L Fs were <5%, and PGs and Ls of each CO were implanted proportionately. Results There were 327 L Fs vs 957 PG Fs, an overall Registry ratio of 34.2%. The combined ratio for the 3 dominant COs was 315/808(40%). Individually the L/PG F ratios were CO A - 50/298(17%); CO B - 92/206(45%); CO C <173/304(57%). L models with 5 or more Fs were: CO A - 1, CO B - 5, CO C - 11. L models on the MHIR Watch List are: CO A - 0; CO B - 2; CO C - 6. The RR for CO A was significantly lower than CO B (0.38–95% CI 0.27–0.53) and CO C (0.29 – 0.22–0.4). There was no sig difference between COs B and C (0.78 – 0.61–1.01). Conclusion There was a substantial difference in need to replace Ls for mechanical and functional F when the 3 highest volume COs were compared. The comparative RRs for L/PG Fs were in agreement with a CO's number of L models with frequent F reports and the number of L models (some recalled some not) on the MHIR Watch List. L design and model selection appear to affect healthcare costs and patient safety. Independent analyses of relative product F rates should encourage COs to provide more thorough premarket testing and earlier recall of high-risk products.
| 10-1 USE OF PHYSIOLOGIC PACING POST CTOPP GFO Tyers M Gao RI Hayden R Leather T Ashton M Kiely British Columbia Cardiac Registry, Vancouver Purpose To determine the effect of CTOPP on mode selection in Western Canada. CTOPP completed enrolment in Feb 96 and by 2000 demonstrated an 18%
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in atrial fibrillation (p<.05) and a 9.4% 
ed from 130 in 97 to 157 pM in 02, giving an 02 total implant rate of 667 PG pM. Over the 6-yr period, the use of AAI±R + VDD±R PG was low and
| 10-2 Indications for pacemakers in the real world: do they follow official guidelines? The Ile de France 2001 regional survey Dr S.Torre*, J.Lacotte, C.Himbert, F.Hidden-Lucet, R.Frank. *CRAMIF, and Unité de Rythmologie, Institut de Cardiologie. G.H. Pitié-Salpêtrière, Paris, France A survey of all 2001 first pacemaker implant were done in Ile de France region. 6414 devices were registered in 49 centers: 329 (5%) in 12 small centers (<50 implantations/year), 2923 (47.5%) in 29 medium centers (50–200/year) and 2902 (47.5%) in large centers (>200/year). 34% of all cases (2176 patients) were drawn in each center for a proportional selection to get a precision of 2.7%. Pacemaker's indications were compared to 2002 ACC/AHA/NASPE guidelines by experts from French Health Care System* and classified according to class 1, 2 or 3 indications. A class 3 indication was found in 8% of overall implantations. They are significantly less frequent in large centers and mainly concern asymptomatic or drug-induced sinus node dysfunctions: 74.5% of class 3 implantations, representing 15.5% of sinus node dysfunction implantations. Others implantations defined as class III were AV blocks (11%), bi or trifascicular blocks (7.5%) and neurocardiogenic syncope (7%). These results are in keeping with those previously reported in Alsace (1999).
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| 10-3 IMPROVED LONG-TERM SURVIVAL IN PACEMAKER PATIENTS OVER 4 DECADES OF PACEMAKER IMPLANTATIONS. Hegbom F1, Gjersdal A1, Brannsten H1,. Sandvik L2, Grendahl H1, Platou ES1. 1Dept. of Cardiology,2 Center of Clinical Research, Ullevål University Hospital, Oslo, Norway. Background: Long-term survival in 2272 (50.5%M/49.5%F) pacemaker patients (PM) implanted from 1961–1999, was compared with age- and sex matched survival from the general population (GP) during the periods 1961–79 (A; n=724) and 1980–99 (B; n=1548). Results: Median age at implantation was 76.0 years. The indication AV-block comprised 60.5%, sick sinus syndrome 28.6%, atrial fibrillation 9.8% and others 1.1%. AV-synchronous pacing was used in 0% in 1961–79, 15% in 1980–89 and 49% in 1991–99. All patients were followed for a minimum of 1 year (mean 16.0±9.1 years) and 83% for a minimum of 5 years. Five-years survival in PM and GP was 52.3% vs. 74.5% in period A and 57.4% vs. 69.7% in period B. The difference in survival PM vs. GP between period A and B was highly significant (p<0.001).
Age, sex and ECG group adjusted 5-years survival for PM in period A and B were 51.2% and 61.2%, and the relative risk of dying in period B vs. A was 0.73 (95% CI 0.63–0,84; p<0.001). Conclusions: Compared to an age-and sex matched general population, PM survival improved over 4 decades of pacemaker implantation.
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| 10-4 INFLUENCE OF THERAPEUTIC IRRADIATION ON THE LATEST GENERATION OF PACEMAKERS C.W. Hurkmans (1), PhD, E. Scheepers (2), B.G.F. Springorum (3), G.S. de Ruiter (3), MD, G.J. Uiterwaal (3) (1) Department of Radiotherapy, Catharina Hospital, Eindhoven, The Netherlands (2) Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands (3) Department of cardiology, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands Introduction: Guidelines for radiotherapy of patients with a pacemaker have been published in 1994 by The American Association of Physicists in Medicine. However, pacemaker technology has evolved rapidly since then. Data on the influence of radiotherapy on modern pacemakers are limited. The objective of our study is to determine the influence of radiotherapy on the latest generation of pacemakers. Materials and Methods: Nineteen pacemakers (Medtronic, Vitatron, Guidant, St. Jude Medical) were irradiated using a 6 megavolt photon beam. The given dose was fractionated up to a cumulative dose of 120 Gy. Frequency, output and sensing have been monitored. Results: 6/19 devices showed atrial and/or ventriculair inhibitions before 5 Gy. Breakdown occurred for 9/19 pacemakers: telemetry failure (at 10 and 120 Gy), premature battery failure (at 120 Gy), loss of output (at 80, 90, 100, 100, 110 and 120 Gy). The sensitivity of the only uni-polar specimen had variations of 100% between fractions. Conclusion: Modern pacemakers are substantially influenced by radiotherapy. However, they do not seem to be much more sensitive than older pacemaker types.
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| 10-5 ELECTROMAGNETIC INTERFERENCE FROM WIRELESS VIDEO-CAPSULE ENDOSCOPY ON IMPLANTABLE PACEMAKERS Dubner Sergio, Dubner Yael, Gallino Sebastian, Spallone Lili, Zagalsky David, Rubio Horacio, Goldin Eran. Clinica Suizo Argentina and Hadasahh Hospital, Israel Objective: This study was designed to evaluate possible interactions between M2A video-capsule (Given Imaging System), a newest system of wireless endoscopy, and implanted pacemakers Methods: The M2A was tested in 100 consecutive patients with an implanted pacemaker (95 on bipolar mode and 70 males). During continuous electrocardiographic recording, 100 tests were carried out at current settings using the TestCap, a functional testing tool for the Given diagnostic system and those with positive results were tested once again. Results: The 100 pacemakers evaluated in the population were as follows: 70 dual-chamber -9 DDD, 56 DDDR, 5 VDD and 30 ventricular-inhibited -12 VVI and 18 VVIR pacemakers; 39 Pacesetter, 32 Medtronic, 15 Guidant, 13 Biotronik and 1 Sorin. In 4, a reproducible undersensing was induced during TestCap operation. Three of them using a dual chamber (Affinity, Trilogy and Logos) and the remaining patient a single chamber (Actros). None of the implanted pacemakers tested were affected by oversensing. According with these results, Pacessetter's devices presented a 5% of undersensing and Biotronik's 15% (Odds ratio 3.3; p= 0.23). Conclusions: Interference from the M2A capsule to the pacemakers was low and not significant to the patient. There were no potentially dangerous pacemaker inhibitions. Our findings showed that the M2A video-capsule caused electromagnetic interference in the form of undersensing in only 4% of the 100 patients tested.
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| 10-6 COMPLICATIONS ARE INFLUENCED BY OPERATOR EXPERIENCE, MORBIDITY AND CHOICE OF PACING SYSTEM Frank Eberhardt, Frank Bode, Hendrik Bonnemeier, Werner Peters, Uwe KH Wiegand, Medical University Luebeck, Cardiology, Luebeck, Germany Purpose: Complication rates of pacing varies between registries and prospective studies. Possible explanations are differences in comorbity and surgical experience. Methods We analyzed records of 1884 VVI, VDD or DDD pacemaker implantations between 1990 and 2001. Operation time (OT) and rate of complications requiring surgical intervention (CR) were analyzed for influence of age, sex, coronary artery disease, myocardial infarction, left ventricular (LV) function, right ventricular (RV) dilatation, sinus node disease, atrial fibrillation and subclavian puncture. Surgical experience (Ex) was graded according to the number of implantations counting each device group independently: ExI 50. Follow-up was 61 ± 33 months. Results: OT was significantly prolonged by the presence of coronary artery disease, inferior myocardial infarction, reduced LV-function and RV-dilatation. Implantation of DDD-pacemakers significantly prolonged OT, particularly in ExI and ExII (left panel). Age >74 years, reduced LV-function, RV-dilatation and DDD implantation were independently predictive for a higher CR. After correction for covariates, a higher CR of DDD was still observed in ExI and ExII, but not in ExIII (right panel). Conclusion: CR is influenced by age as well as left and right ventricular diseases. In ExIII, CR does not substantially differ between DDD, VDD and VVI pacing. Learning curves appear to be steeper in VDD pacing; this might be an argument for use of VDD pacing in AV block.
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| 10-7 The Austrian Pacing registry K. Steinbach, Austrian Heart Foundation, Ludwig Boltzmann institute on Arrhythmia Research Background: Registries are useful to collect epidemilogical data, to observe trends, to compare different departments, to control quality of treatment and to reduce costs. In this paper some examples for evaluation of trends are given. Patients: Data of 73.138* pts (34.942f 38.196m) and 90.435 PM collected between 1.1.80–31.12.2003 from 61 implanting hospitals (99% participation of PM implanting hospitals in Austria) Results: 1) Continuous increase of implantation rate (IR) in pts between 70 and 79y (25 to 47%) and continous decrease of IR in pts between 80 and 89y (58 to 19%) of all 1st implants. 2) No significant change of clinical indication syncope (30 vs 32%) and presyncope (21 vs 24%). Decrease of IR of prophylactic implantation (29 vs 18%) and CHF - (11 vs 6%). 3) IR of AV-block (35 vs 32%), Sick sinus syndrome (SSS) (23 vs 17%). Atriai Fib/Flu (16 vs 20%) in prepacing ECG changed only slightly. IR of Brady/Tachy syndrome (B/T -S) doubled (5 vs 12%). 4) In 2003 91% of. pts with SSS. 82% of pts with AV-block received a physiological PM. 5) In 2003 25% of pts with the indication CHF received a biventricular PM. Summary. 1) Population above 80y seem to be less affected by bradyarrhythmias during the 23y the registry is in operation. 2) No significant change of clinical indications for PMI. 3) New pacing modes explain ihe higher percentage of PMJ in pts with B/T-S especially as preventive measure. 4) The high percentage of physiological pacing as well in SSS as AV-block reflects the opinion of PM-Implanters. that this mode is superior to right vernacular pacing in both indications. 5) Biventricular pacing still is ased oniy in a low number of pts with CHF and is still classified as experimental procedure.
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| 13-1 CONSEQUENCES OF APPROPRIATE AND INAPPROPRIATE THERAPY IN PATIENTS WITH ICD 1Defaye P, 2Delay M, 3Davy JM, 3Pasquié JL, 4Bizeau O, 5Le Marec H, 6Azoui R, 7Leenhardt A, on behalf of OPERA study investigators. 1University Hospital Grenoble, 2University Hospital Toulouse, 3University Hospital Montpellier, 4University Hospital Orléans, 5University Hospital Nantes, 6Guidant France, Rueil-Malmaison, 7University Hospital Lariboisière Paris Introduction: The development of new detection algorithms in the implanted cardioverter defibrillator (ICD) may reduce inappropriate therapy. The aim of the OPERA study was to evaluate the incidence of appropriate therapy and inappropriate therapy in patients implanted with PRIZMTM or VITALITYTM ICD (Guidant). Methods: Among 343 patients (pts) enrolled in OPERA study (295 men, mean age 60.7 ± 14.3 years, mean LVEF 41 ± 16%), 25.6% had a prophylactic ICD indication. NYHA Class II and III were respectively 50% and 10%, 194 pts (56,5%) had coronary artery disease and 27% of pts had a history of atrial arrhythmias. Mean tachycardia detection rate was 164 ± 20 bpm and 17% of devices were programmed with a low tachycardia detection zone at 143 ± 16 bpm. Results: During a 6-month follow-up, 43 (12.5%) pts have received the first appropriate therapy (AT) due to ventricular tachycardia for 79% of them. The first inappropriate therapy (IAT) had occurred in 14 (4%) pts. The delivered therapies and their clinical consequences in terms of hospitalization (H), emergency follow-up (E), drug change (DC), and programining modification (PrM) are reported in the following table:
Conclusion: These preliminary results show a lower percentage of inappropriate therapy than previously reported in the literature. Nevertheless, shocks are delivered in 86% of these IAT, leading to an increase of hospitalizations and emergency follow-ups.
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| 13-2 INCIDENCE OF INAPPROPRIATE DETECTION AND THERAPY OF ARRHYTHMIAS IN PATIENTS WITH PROPHYLACTIC DEFIBRILLATORS. Uma Srivatsa, Bobby Hoppe, Gregory K. Feld, Ulrika Birgersdotter-Green. University of California San Diego, USA Background: Inappropriate ICD therapy due to false detection of arrhythmias is common, and may be reduced by programming Ventricular Arrhythmia Discriminators(VAD) at the time of device implantation. Methods/Results: In 45 patients(age 62±15) with EF 28±8% who had prophylactic implantation of conventional or biventricular ICD, followed prospectively for mean 123±104 days, there were 29 events detected in 15 patients, including ventricular arrhythmia (n=12), sinus tachycardia (n=9), atrial fibrillation(AF)(n=5) and pacemaker mediated tachycardia(n=3). Arrhythmias were correctly identified in 17 of 18 events and incorrectly identified in 9 of 11 events when VAD were programmed ON or OFF respectively (p<0.001). Of the algorithms utilized PR logic (p=0.009), AF(p<0.001), atrial flutter(AFL)(p<0.001) and V>A rate(p=0.016), significantly enhanced appropriate detection, while onset and stability were not effective. For non-ventricular events, diagnosis was appropriate 83.3% and inappropriate 81.8% of the time when VAD were programmed ON or OFF respectively(p =0.009). PR logic(p=0.006), AF(p=0.009), AFL(p=0.009) were the most useful algorithms in differentiating ventricular from non-ventricular events. There were a total 10 shocks delivered in 3 patients during followup. The incidence of inappropriate shocks were more likely if VAD were not programmed at implantation(p<0.001). Conclusion: Programming Ventricular Arrhythmia Discriminators ON at ICD implantation significantly improved detection and classification of arrhythmias, resulting in appropriate therapy. PR logic, AF, AFL and V>A algorithms were the most effective in differentiating ventricular from non-ventricular events.
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| 13-3 Incrementing dual-chamber ICD specificity by interval stability monitoring Robert Bowes, Ralph Mletzko1, Frederic Anselme2,, Wolfgang Schoels3, Marc Delay4, Nicolas Iscolo5, Rémi Nitzsché5, Nicolas Sadoul6, on behalf of the "Slow VT Study" Investigators. Northern General Hospital, Sheffield, UK, 1Herz-Kreislauf Klinik, Bad-Bevensen, Germany, 2Rouen University Hospital, France, 3Heidelberg University, Germany, 4Toulouse University Hospital, France, 5ELA Medical, Le Plessis-Robinson, France, 6Hôpital Brabois, Nancy, France. Inappropriate therapy remains an important limitation of implantable cardioverter defibrillators (ICD). PARAD+ detection algorithm was developed to increase the specificity conferred by PARAD in the detection of atrial fibrillation (AF).
Methods. To compare the performances of the 2 different algorithms, we retrospectively analyzed all spontaneous and sustained episodes of AF and ventricular tachycardia (VT) documented by dual-chamber ICDs (Defender IV and Alto DR, ELA Medical, France) programmed with PARADTM or PARAD+TM at the physicians' discretion. The results were stratified according to tachycardia rates <150 versus Results. During a mean follow-up of 11 ± 3 months, 1019 VT and 315 AF episodes were documented among 338 devices. For slow tachycardias the sensitivity of PARAD vs. PARAD+ was 96% vs. 99% (NS), specificity 80% vs. 93% (p<0.002), positive predictive value (PPV) 94% vs. 91% (NS), and negative predictive value (NPV) 86% vs. 99% (p<0.0001). In the fast VT zone specificity and PPV of PARAD (95% vs. 84% and 100% vs 96%) were higher than those of PARAD+ (NS and p<0,001). Among 23 AF episodes treated in 16 patients, 3 episodes triggered an inappropriate shock in 3 patients, all in the PARAD population. Conclusions. PARAD+ significantly increased the ICD diagnostic specificity and NPV for AF in the slow VT zone without compromising fast VT detection.
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| 13-4 PERFORMANCE OF A SINGLE CHAMBER ICD WITH THE RHYTHM ID ALGORITHM Raffaele Corbisiero, Michael A. Lee, David R. Nabert, Michael C. Giudici James A. Coman, David J. Breiter, Mark J. Schwartz, Yunlong Zhang INTRODUCTION: A new dual chamber supraventricular tachycardia (SVT) algorithm, Rhythm ID, utilizes both conventional "V>A", "AFib Threshold", and "Stability" algorithms, and a vector timing and correlation (VTC) algorithm. In the single chamber configuration, Rhythm ID contains only the VTC component. This study retrospectively analyzed the performance of Rhythm ID to induced and spontaneous rhythms in a single chamber configuration. METHODS: This study was a prospective, multi-center trial and 96 patients were implanted with a dual chamber ICD at 21 U.S. centers. Patients were followed at 1-month and every 3-months post implant. Each episode was analyzed to identify the performance of the Rhythm ID algorithm in the single chamber configuration. RESULTS: The mean age of the patients was 67 ± 11 years (78 male). A total of 359 induced and spontaneous ventricular arrhythmias were analyzed. The algorithm detected all ventricular arrhythmias. A total of 442 SVT episodes were analyzed (145 induced, 297 spontaneous). The SVTs and respective specificities were sinus tachycardia, 71% (n=70), atrial tachycardia, 89% (n=34), atrial flutter, 93% (n=135), atrial fibrillation, 97% (n=199) and non-classified SVT, 100% (n=4). The single chamber Rhythm ID configuration successfully discriminated 403 SVT episodes and achieved a device specificity of 91%. CONCLUSION: The single chamber Rhythm ID algorithm had 100% sensitivity to ventricular arrhythmias and an overall specificity of 91% to SVTs. The algorithm also had very high performance to AF and AFL (97% and 93% respectively). These results demonstrate that the Rhythm ID algorithm in the single chamber configuration achieves clinically acceptable sensitivity and specificity.
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| 13-5 Improving Single Chamber (CD Specificity by Singie A-V Lead A. Curnis1, T. Toselli2, D. Igidbashian3, P. Delise4 on behalf of the Italian ADAMO Registry group - Brescia, Ferrara, Legnago, Conegliano; Italy In single chamber ICDs the main cause for inappropriate shock delivery is improper discrimination of SVT from VT because the lack of atrial sensing. ICDs mod. Belos A+ and DeiKos A+ (Biotronik, D) achieve atria! information through a floating atrial electrode placed on the defoliation single A-V lead mod. Kainox VDD. Improvement of specificity is assured by the SMART algorithm. Aim of the ongoing ADAWO registry is to assess if specificity and sensitivity of SMART algorithm implemented in these devices are comparable to those achieved in dual-chamber ICDs using the same algorithm (93% and 100% respectively). iAt present, 42 pts (32 m, 63±12 y, EF 37±11%, NYHA 1.9±0.6) were enrolled as complying Class I (n=26) or Class II (n=10) ACC/AHA guidelines for single chamber ICD therapy or MADIT II indications (n=6). Pts with chronic AF or SSS were excluded. FU is performed at 2,4,8 and 12 mo. Mean value at implantation were: P-wave 3.1±1.0 mV; R-wave 11.2±3.6 mV; Pacing Threshold 0.5±0.2 V; Effective Shock Energy 17.4±2.4 J and Shock Impedance 70±11 ohm.O Mean total implant and fluoroscopy times were 40±20 and 6.5±5,6 min. respectively. Cumulative FU is 366 mo. During FU at 2, 4, 8 and 12 mo., P-wave amplitude was 2.9±1.4 mV, 3.2±1.0 mV, 2.6±1.2 mV and 2.0±1.4 mV respectively. Memorized IEGMs evidenced: 15 episodes (eps) (n=5) of AF and 54 eps of SVT (n=16) recognized by SMART, 41 eps (n=7) of slow VT/VF interrupted by ATP or shock. In 4 pts inappropriate ATP/shocks were delivered for: T-wave oversensing (n=2), lead displacement (n=1) and atrial undersensing (n=1). Rate of detected atrial signals was 92.7% and 98.9% during AF and SVT respectively. Preliminary data of the ADAMO study are quite positive. The VDD-ICD seems to have high sensitivity and specificity; the system is easy to implant thanks the single-lead approach and it could represent a concrete alternative in most pts in which a single or dual chamber ICD should be implanted.
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| 13-6 IS BI-VENTRICULAR ANTI-TACHYCARDIA PACING MORE EFFECTIVE THAN RIGHT-VENTRICULAR ANTI-TACHYCARDIA PACING? Berthold Stegemann, Johannes Heintze*, Jürgen Vogt*, Bart Gerritse, Sandra Jacobs, Bart Gerritse: Bakken Research Center, Maastricht, Netherlands; *Herz- und Diabeleszentrum NRW, Bad Oeynhausen, Germany Aim: Combination devices such as the InSync ICD (Medtronic Model 7272) offer independent programmability of CRT and anti-tachycardia pacing (ATP). The majority of VT originate from the left ventricle and ATP efficacy should thus be higher for bi-ventricular (BV)-ATP. Methods: The InSync ICD study enrolled 89 pts in NYHA II-IV, LVEF<35% and QRS width >130 msec. We retrospectively analyzed VT episodes from the device with true spontaneous VT onset, delivery of at least one ATP therapy and known ATP efficacy. First-therapy ATP efficacy was analysed using a logistic GEE model. Results: 26 pts experienced 610 VT episodes. 569 VT episodes in 23 pts fulfilled all criteria above. First ATP therapy was successful in 494 episodes (86.6%). BV-ATP was programmed in 10 pts and to RV-ATP in 16 pts; 3 pts had both modes programmed at different times. Logistic GEE model efficacy estimates of first-therapy efficacy were 88.7% (CI:80.7–93.6%) for BV-ATP and 68.3% (CI:49.7–82.4%) for RV-ATP. The difference is significant (p=0.0006). Only VT cycle length, presence of ACE-inhibitors and statins significantly added to the model. Controlling for this covariates first-therapy efficacy were 91.7% (CI:83.5–96.0%) for BV-ATP and 77.5% (CI:55.2–90.6%) for RV-ATP (p=0.01). Conclusions: ATP therapy is effective in patients with heart failure. BV-ATP is significantly more effective, even after correction for VT cycle length and cardiac medication, This clinical effect needs to be confirmed prospectively.
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| 14-1 PATIENTS UNDERGOING CARDIOVERTER-DEFIBRILLATOR TREATMENT: HIGHEST RISK OF CARDIAC DEATH HAS BEEN OBSERVED DURING THE FIRST YEAR AFTER IMPLANTATION. A LATIN - AMERICAN COOPERATIVE REGISTRY: THE ICD-LABOR R Pesce, JC Pachon Mateos, E Valero, R Garillo, C Conejeros Kindell, H Sgarlatta, S Dubner, JL Montenegro, S González, on behalf of the ICD-LABOR investigators. Fleni, I Dante Pazzanese, Universidad del Salvador, H Barros Luco, S Allende, S Suizo, CASMU, I Cardiología. Introduction: The ICD-LABOR registry includes 7 Latin-American countries, 91 medical centres, 125 investigators and 632 patients (pts) distributed as: 247 (39%) coronary artery disease (CAD), 171 (27%) Chagas' disease (ChD), 110 (17.5%) dilated cardiomyopathy (DCM), and 104 (16.5%) as Miscellaneous(this last group were not analyzed in the present paper). Methods: Of the remaining 528 pts. age, gender, pacing and defibrillation threshold, ejection fraction (EF), mode of outcome and follow-up period were analyzed. Results: During the follow-up period of 24 ±22 months (range 1–168 months), 69 cardiac deaths were registered and they were divided in two areas: early death (ED)(within the first year post implantation), and late death (LD)(beyond the first year). In the CAD Group, 24 EDs (EF 27.5%±12) and 13 LDs (EF 37.4%±12) were reported, p<0.0288. In the cardiomyopathy (CM) Group, (DCM+ChD), 16 EDs (EF 26.8% ± 6.9), and 16 LDs (EF 25%±4.8)were reported p=NS. Looking exclusively of EDs: non-sudden cardiac death was predominant in CAD Group (17 of 24)versus CM Group (2 of 16) p<0.0039 Conclusion: 1. EF had predictive value of risk of cardiac mortality in the first year of follow-up only in CAD pts., 2.- Among the data analyzed there were no predictors of mortality in CM Group, 3.- Among ED patients, non sudden cardiac death was statistically higher in CAD pts than in CM pts.
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| 14-2 Incidence and outcome of primarily untreated slow ventricular tachycardia in ICD patients. E. Adornato1, W. Schoels2, F. Anselme3, A. Pangallo1, V. Pennisi1, R. Mletzko4, M. Delay5, N. Iscolo6, N. Sadoul6, on behalf of the Slow VT Study group. 1A.O. Bianchi-Melacrino-Morelli, Reggio Calabria, Italy; 2Universitatskliniken, Heidelberg, Germany; 3University Hospitals, Rouen; 4Herz-Kreislauf-Klinik, Bad-Bevensen, Germany; 5Toulouse and 7Nancy University Hospitals, France; 6Ela Medical, Le Plessis-Robinson, France. Incidence and clinical tolerance of slow ventricular tachycardia (VT) have not been fully studied in general ICD population. The "Slow VT Study" was a prospective study, in which therapies in the slow VT detection zone (101–148 bpm) were randomised on or off. We report the prevalence and the cilinical outcome of slow VT in the group of patients (pts) with no therapy in the slow VT detection zone. Methods. Pts were eligible in the study if they had class I indication for dual chamber ICD and no prior history of symptomatic slow VT. All pts received Defender IV or Alto DR ICDs (ELA Medical, France). One hundred and eighty eight pts were enrolled (168 males, 64±10 years, LVEF 0.38±0.15). Slow tachycardia episodes (eps) were recorded over a 1 year follow-up period. Results. VT was identified in 192/3058 recorded eps of slow tachycardia in 51 pts. Among these eps, 153 (80%) in 49 pts terminated spontaneously (sp.) or decelerated below 101 bpm (duration: 7,6±22,5 min), 12 (6%) accelerated above 148 bpm and were subsequently treated, 27 (14%) were detected and treated after slow VT therapies activated by the physician. This activation was required because of re-hospitalisation for heart failure (n=3 pts), or occurrence of palpitations or dizziness (n=7 pts). Pts with slow & fast VT (31) presented a greater number of slow VT as compared to pts with slow VT only (18) (Wilcoxon test). Conclusions. More than 25% of the study population presented with unexpected slow VTs. Activation of slow VT therapies was required in 5% of the slow VT pts population during FU.
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| 14-3 DFT AND HEART FAILURE IN ICD PATIENTS WITH SINGLE OR DUAL COIL LEADS Xiaoyi Min, Ph.D. Xiaozheng Zhang, MD, Jennifer Studt, St. Jude Medical Sylmar, CA, William H. Kou, MD, Ann Arbor VA Hospital, Ann Arbor, MI, Thomas Deering, MD, Piedmont Hospital, Atlanta, GA, Steven Keim, MD, Lakeland Regional, Lakeland, FL, Larry Rosenthal, MD, Univ. of Massachusetts, Worcester, MA Purpose: It was reported that high DFT may be associated with worsened NYHA, low EF and LV dilation. However, it is unclear whether the outcomes were specific to shocking electrode systems. We evaluated lead system on relationship of DFTs to NYHA and EF. Methods: The analysis included 302 ICD patients (pts) (age 66±12 years, 83% male), 234 had dual coil and 68 had single coil leads. The correlations of DFTs with NYHA and EF were tested using Spearman Correlation. DFTs were further compared between pts with NYHA I&II and NYHA III&IV, and pts with EF<35% and EF>35%. Results: DFT (J) correlated inversely with NYHA in pooled data (p=0.03). However, the correlation trend was only consistent with pts had dual coil leads (r=-0.2, p=0.001). Further analysis showed dual coil leads pts with NYHA III&IV had lower DFTs compared to NYHA I&II (14±6J vs. 16±5J, p=0.02); pts with EF>35% had higher DFTs compared to EF<35% (16.7±5.7J vs. 15.3 ± 5.1 J, NS). The reversed results were seen in pts with single coil leads (NS). Conclusion: The trend in DFT as NYHA class worsened is lead system dependent. DFT trend in single coil pts is consistent with early published data. However, heart failure progressed fluid overload in the connective tissue may increase current flow from SVC coil to posterior LV free wall, thereby reducing DFT with dual coil lead system.
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| 14-4 CAN THE IMPLANTABLE CARDIOVERTER/DEFIBRILLATOR AVOID ARRHYTHMOGENIC SYNCOPE? Przibille, Oliver; Himmrich, Ewald; Andreas, Klaus; Nebeling, Dirk; Theis, Cathrin; II. Medical Clinic, University Hospital Mainz, Germany Aim: Analysis of syncopes in pts. with ICD and time frame during which the first syncope occured. Are there any predictive factors? Method: We retrospectively analyzed 165 pts. with appropriate ICD therapies (97% shock, 3% ATP only) and a follow-up > 24 months (67±29). Patient cohort: m 132, f 33; age 59.6±12 yrs; CHD 58%, idiopathic cardiomyopathy 24.8%, other cardiac disease 27.2%. Results: 82/165 pts. (49.7%) had syncopes due to ventricular tachyarrhythmias treated by the ICD ; 42 pts. had > 1 syncope. Pts. with and without syncope did not differ in age, sex, underlying heart disease, LV ejection fraction (41±15 vs. 42.7±17%): NYHA classification or syncopal episodes before ICD implantation. There was no correlation between incidence of syncope and LV-EF or number of ICD therapies. Tachyarrhythmias causing syncope were significantly faster (263±47 vs. 206±43 bpm). The mean time interval between ICD implantation and first syncope was 29.1±25 months. In only 40.2% of the pts. it occurred during the first 6 months after implantation and in 52.4% during the first year. The syncope-free survival of patients is shown in the following table:
Conclusion: Half of the patients with appropriate ICD therapies suffer from arrhythmogenic syncope. The individual risk cannot be predicted and the syncope-free interval after implantation shows an enormous variation. Since the ICD cannot prevent arrhythmogenic syncope, this risk must be considered when giving pts. advice about activities of daily life (driving, swimming, etc.)
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| 14-5 VT AND ATP THERAPY IN ICD PATIENTS WITH CORONARY ARTERY DISEASE AND LV DYSFUNCTION 1Thomas Deering, MD, 2Jennifer Studt, 2James Tyler, 3Bill Kou, MD, 4Steven Keim, MD, 5Larry Rosenthal, MD, 6Alaa Shalaby, MD, 2Bruce Meredith, 1Piedmont Hospital, Atlanta, GA, 2St. Jude Medical CRMD, Sylmar, CA, 3Ann Arbor VA Hospital, Ann Arbor, MI, 4Lakeland Regional, Lakeland, FL, 5University of Massachusetts, Worcester, MA, 6Pittsburgh VA Medical Center, Pittsburgh, PA Purpose: Although MADIT II demonstrated that implantable cardioverter defibrillators (ICDs) improve survival in patients with a left ventricular ejection fraction (LVEF) <30% and a previous MI, the incidence of VT and ATP therapy in this population is unknown. Methods: Seventy-seven patients with a history of CAD and LVEF <30% (mean 22±6%) were identified from 3 multi-center studies followed for at least 6 months after implantation. The average age was 66.5±9.7 years; 73.9% had experienced NYHA class II-IV congestive heart failure (CHF) 88.3% were male. Results: Nineteen (24.7%) patients had 360 episodes of appropriately diagnosed VT (mean cycle length of 394±48.1 ms). Sixty-nine (19.2%) of these episodes were successfully reversed by ATP. The remaining 80.8% episodes either terminated spontaneously or were terminated by shock therapy. Conclusion: VT is a relatively common arrhythmia occurring in patients with an ischemic cardiomyopathy and LVEF < 30% who undergo ICD implantation for primary prophylaxis. Enabling ATP, if it is available in the ICD, may reduce the morbidity of symptoms secondary to painful shock therapy.
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| 14-6 FREQUENCY OF ADEQUATE ICD INTERVENTIONS IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY AFTER ICD IMPLANTATION FOR PRIMARY PREVENTION H. Buschler, J. Vogt, B. Lamp, J. Heintze, D. Horstkotte, L. Faber. Department of Cardiology, Heart Center North Rhine-Westphalia, Ruhr University of Bochum, Bad Oeynhausen, Germany
For patients (pts) with hypertrophic cardiomyopathy (HCM) a number of risk factors concerning sudden cardiac death (SCD) have been proposed (syncope, family history of SCD, non sustained ventricular tachycardia (nsVT) on Holter, abnormal blood pressure response during exercise, LV wall hypertrophy >30 mm). Prophylactic ICD implantation has been recommended, if two or more risk factors are present. In our cohort of >800 pts with HCM we identified 20 pts, in whom we implanted an ICD as primary prophylaxis of SCD according to these criteria. The cohort consisted of 4 women, 16 men, mean age 40 ± 14.2 years (15–65 y), 12 PTs with HOCM, 8 Pts with HNCM, 1 pt with additional CAD after PTCA, NYHA class 2.0 ± 0.8. The majority of pts received conventional beta-blocker, 1 p had Amiodaron, 2 pts had Verapamil. NsVT was present in 15 pts, 11 had syncope, 8 had a family history of SCD. 17 pts. Underwent an electrophysiologic study in order to exclude supraventricular arrhythmias, 11 of these (65%) had inducible VT/VF. All pts received a dual chamber ICD. During a mean follow up of 13.5 (3 Fifteen percent of high risk pts with HCM after ICD implantation for primary prevention of SCD received adequate therapies because of VF or fast VT during a FU of only 13 m. The incidence of malignant arrhythmias in this cohort is high and ICD implantation should be strongly considered.
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8) months (270 patient months) 4 adequate ICD interventions in 3 pts were documented: 1 p with 2 episodes of VF, 2 p with sustained VT. Inadequate ICD interventions because of sinus tachycardia and T wave oversensing occurred in 1 p.
| 17P-1 IS A PROVOCABLE BRUGADA SIGN IN ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA-CARDIOMYOPATHY A MARKER OF INCREASED ARRHYTHMOGENIC RISK? Peters S, Trümmel M, Koehler B - Cardiology, Quedlinburg, Germany In 10–15% a Brugada-type ECG can be induced by drug challenge in arrhythmogenic right ventricular dysplasia_cardiomyopathy (ARVD/C). In typical Brugada syndrome an increased arrhythmogenic risk is present in cases with documented arrhythmias and aborted sudden cardiac death (recurrence rate 50%) and in cases of syncopes (recurrence rate 15%). The question is whether Brugada sign in ECG represents a marker of increased arrhythmogenic risk in ARVD/C, too. Systematic ajmaline testing (1mg/kg) in 82 patients with ARVD/C according to ISFC/ESC criteria could induce Brugada sign in 14 cases (17%) - 3 males und 11 females. Syncopes were present in 5 cases (36%); one female patient had aborted sudden cardiac death. During EP study only in one patient monomorphic ventricular tachycardia could be induced. 4 patients were treated by ICD implantation. Conclusions: A provocable Brugada sign is associated with moderately to highly increased risk of clinical events in nearly half of all patients and represents a strong marker of increased arrhythmogenic risk also in patients with ARVD/C.
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| 17P-2 A CASE OF A SHORT COUPLED VARIANT OF TORSADE DE POINTES WITH A PROMINENT J WAVE Takeuchi T, Nakagawa N, Tanabe Y, Takahashi F, Sato M, Sato N, Kawamura Y, Hasebe N, Kikuchi K - 1st Dept. Internal Medecine, Asahikawa Medical College, Japan We present a case with a short coupled variant of Torsade de pointes (Tdp), whose recurrent episodes of ventricular fibrillation (VF) were suppressed by the combination therapy of oral verapamil and mexiletine, and in which a prominent J wave was diminished by the verapamil. The patient's frequent VF attacks were triggered by short-coupled premature ventricular contractions (PVCs) with a right bundle branch block morphology and left axis deviation. In the electrophysiologic studies, VF was not induced with up to three consecutive extrastimuli or burst stimulation from the right ventricular apex or right outflow tract, either in the baseline state or during the infusion of isoproterenol. Further, no ST segment abnormalities were induced by autonomic receptor stimulation or blockade, such as with methoxamine, edrophonium or procainamide. However, an intravenous administration of atropine resulted in VF triggered by a short coupled PVC, which lead to an electrical storm. Finally, the VF attack was completely suppressed by deep sedation followed by the combination therapy of oral verapamil and mexiletine.? Interestingly, with oral mexiletine therapy, prominent J waves were still observed in leads V3-V6 in the patient, and his daughter also exhibited a similar pattern of early repolarization or J waves in the precordial leads. On the other hand, after adding oral verapamil, the prominent J waves on the electrocardiogram and VF attacks almost completely disappeared. These results suggest new evidence that (1) abnormal verapmil and mexiletine sensitive tissues may contribute to the short coupled variant of TdP, and (2) verapamil is effective for this syndrome probably caused not only by suppressing the triggered activity, but also by surpressing the transient outward current and reducing the transmural voltage gradient responsible for the J waves in some particular cases.
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| 17P-3 ATRIAL FIBRILLATION IN PATIENTS WITH WOLFF-PARKINSON-WHITE SYNDROME R. Batalov, S. Popov, I. Antonchenko, V.Aleev Research Institute of Cardiology, Tomsk, Russia Occurrence of atrial fibrillation(AF) in patients with Wolff-Parkinson-White (WPW) syndrome, burdens clinical course especially at patients with demonstrating forms of WPW. At the same time presence of additional anatomic junction between atria and ventricle results itself in development of AF, that is especially not typical of young patients of the general population, without organic heart pathology. The purpose of the research: Comparison of duration of disease and development of atrial fibrillation in patients with WPW syndrome. Material and methods. 220 patients with WPW syndrome were included into research. From them: with manifesting - 118, concealed - 76 and latent - 26. All patients underwent Electrophysiological study with the subsequent successful radiofrequency ablation of additional atrioventricular junction (AVJ) (Table 1).
Mean age of patients 34,4±16,4 years. Duration of arrhythmological anamnesis in group of patients without AF averaged as 10,3±4,9 years, and in patients with AF 15,1±6,7 (p = 0,003). See figure. Localization of additional AVJ in 139 (63,2%) was left side and in 81 (36,8%) patients - right side. Localization of additional AVJ in patients of two groups is represented in Table 2.
Conclusions: AF occurrence depends on duration of arrhytmological anamnesis. The longer patients have reciprocal tachycardia attacks the higher the risk of AF occurrence. AF occurrence also depends on localization of additional AVJ. Left posterioseptal a position is the most frequently occured. Localization of additional AVJ can serve as a preliminary marker of probable development of atrial fibrillation paroxysms, that it is necessary to take into account during diagnostic pacing and prospective patients' follow-up after ablation.
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| 17P-4 DOES ATRIAL FIBRILLATION CONFER HYPERCOAGULABLE STATE? Beata Wozakowska- KapBon-1), Grzegorz Opolski2), Marianna Janion1) 1.) Dept. of Cardiology Regional District Hospital, Kielce, Poland 2.) Dept. of Internal Medicine and Cardiology Medical University of Warsaw, Poland Atrial fibrillation (AF) is strongly associated with thromboembolic complications, although the mechanism for the increased risk has not been fully explained. It is not clear whether this hypercoagulable state is attributable to the underlying disease or AF alone. The aim of this study was to determine whether AF induce modifications to the coagulation system in patients with heart failure and impaired left ventricle. Methods: Hemostatic markers for abnormalities of hypercoagulability were evaluated in peripheral blood in 17 patients with permanent AF (mean AF duration 6 months) and decreased left ventricular ejection fraction (EF<40%) and in 10 patients with sinus rhythm, matched with age, sex, concomitant diseases and echocardiographic findings. Plasma levels of hemoglobin, hematocrit, fibrinogen, D-dimer and platelet aggregation in respose to ADP were measured. None of patients were receiving anticoagulation therapy before and they did not have a history of embolisation. Results: When compared with the sinus rhythm group (n=10), the AF patients had significantly higher mean hematocrit, hemoglobin, fibrinogen and D-dimer plasma levels: 46,4±4,0% vs 44,2±3,5%; 15,4±1,7 g/dl vs 14,3±1,4 g/dl; 3,78±0,6 g/l vs 2,60±0,5 g/l; 480,8±206,4 ng/ml vs 367,6±192,4 ng/ml, AF vs sinus rhythm respectively;(p<0,05, p<0,05, p=0,05 and p<0,05). In patients with AF 11 out of 17 had hyperaggregable platelets in response to ADP while none had of sinus rhythm group. These results indicate that AF itself enhances platelet aggregation and coagulation. Conclusion: AF itself confer hypercoagulability state regardless of the risk factors of the subjects and the presence of cardiovascular disease and impaired left ventricle. Futher prospective studies are needed to evaluate whether measurement of hemostatic factors will identify patients with AF who are at increased risk for thromboembolic complications and need more intensive antithrombotic therapy.
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| 17P-5 DOES ANTIARRHYTHMIC TREATMENT WITH AMIODARONE ENHANCE QUALITY OF LIFE OF ATRIAL FIBRILLATION PATIENTS REVERTED TO SINUS RHYTHM? Beata Wozakowska-Kaplon1), Grzegorz Opolski2), Marianna Janion1) 1.) Dept. of Cardiology Regional District Hospital, Kielce, Poland 2.) Dept. of Internal Medicine and Cardiology Medical University of Warsaw, Poland Background. Although the assessement of survival is vital to evaluating the efficacy of therapeutic strategies, quality of life (QoL) measurement is important for understanding how these strategies impact the daily lives of patients. Atrial fibrillation (AF) may comprise QoL by several mechanisms: haemodynamic consequences of AF, association with thromboembolism or management inconveniece. The aim of the study was to evaluate QoL in patients with persistent AF before and 6 months after sinus rhythm restoration. Methods: The study group comprised of 20 patients (56,7±6,2 years) with persistent AF (6,7±6,5 months) and 10 control subjects matched with sex, age and concomitant diseases with normal sinus rhythm. The study group underwent cardioversion from AF and was maintaining sinus rhythm following 6 months period with amiodaron administered as a prophylactic treatment. The QoL was measured using generic SF-36 scale (with a physical component summary, PCS, and a mental component summary, MCS) and Brignole AF Symptom Checklist (SCL), at baseline (before treatment) and 6 months after sinus rhythm restoration. Results Patients with AF had substantially impaired QoL compared with control subjects: 37±17 vs 69±21 (p<0,05);44±12 vs 72±23 (p<0,05); PCS and MCS consecutively. Sinus rhythm restoration and treatment with amiodarone appeared to improve QoL in study group: 37±17 vs 44±11 (p<0,05); 44±12 vs 49±11 (p=0,04) and 26±5 vs 21±4 (p<0,05); PCS, MCS and SCL at baseline and over the follow-up period respectively. Conclusion These findings demonstrate health dysfunction for pts with AF. A successful cardioversion and maintenace of sinus rhythm with amiodarone is associated with higher QoL in pts with persistent AF.
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| 17P-6 OCCURRENCE AND TYPE OF REPERFUSION ARRHYTHMIAS IN ACUTE MYOCARDIAL INFARCTION IS INFARCT-RELATED ARTERY DEPENDENT - A HOLTER SUB-STUDY OF THE ASIA PACIFIC MYOCARDIAL INFARCTION TRIAL (APAMIT) Aaron Wong, Li-Fern Hsu, Wee-Siong Teo, Koon-Hou Mak, Ruth Kam, Charles Chan, Tian-Hai Koh, Yean-Leng Lim National Heart Centre, Singapore; Background: Controversy exists as to whether arrhythmias after reperfusion of infarct-related artery (IRA) are secondary to reperfusion alone. This study aimed to determine the incidence and type of arrhythmias related to reperfusion in AMI patients undergoing primary angioplasty (PA). Methods: Holter recordings were obtained from patients with AMI treated with thrombolysis or PA. All patients had coronary angiography, to assess TIMI flow grade, and PA performed if required. Cardiac rhythm was recorded for 24 hours from the time of arrival in cardiac laboratory. The types and occurrence of arrhythmias in patients with initially occluded IRA (TIMI 0 or 1) and successful PA (acute reperfusion group) was compared to a control group, who had patent IRA (TIMI 2 or 3) on initial coronary angiography and remained patent, with or without PA. Results: Fifty-nine eligible Holter recordings (acute reperfusion=23 and control=36) were obtained. The baseline demographics were similar with 83% male and a mean age of 56 years. The IRA was LAD in 44% of patients. Accelerated idioventricular rhythm (AIVR) and sinus bradycardia (SB) were significantly more common in patients with acute reperfusion (65% vs. 39%, p=0.049 and 3% vs. 30%, p=0.004, respectively). AIVR were founded to be more common in acute reperfusion of LAD (67% vs. 28%, p=0.05), whilst SB occurred more frequently in RCA (46% vs. 6%, p=0.02). The occurrence of other arrhythmias was not different between the 2 groups. Conclusions: Acute reperfusion in patients with occluded IRA resulted in significant higher incidence of arrhythmias, suggesting that reperfusion of occluded IRA does induce arrhythmias, and occurrence of specific arrhythmias appeared to be IRA-dependent.
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| 17P-7 QT DISPERSION IN HYPERTENSIVE SUBJECTS WITH "NON-DIPPING" The aim of the study: to compare QT dispersion (QTd) and left ventricular hypertrophy (LVH) between hypertensive subjects with preserved (dippers) or absent (non-dippers) night blood pressure fall. Methods: The study investigated 75 pts (43F, aged 52±15) with essential hypertension. ABPM was performed in all pts. Patients were classified as dippers 54 pts or non-dippers 21 pts according to the magnitude of nocturnal BP fall > or < 10% of diurnal values. LVH was confirmed by ECO using left ventricular mass index (LVMI). QTd was assessed based on 12-leads standard ECGs. Results: Dippers and non-dippers had similar 24h systolic and diastolic BP, while nocturnal diastolic BP was less in dippers than in non-dippers (87,8±14,6 vs 93,0±7,7 mmHg; p=0,025). QTd was greater in non-dippers: 51,4±11,5 ms than in dippers: 44,4±13,4 ms; p=0,015. LVMI was significantly greater in non-dippers than in dippers. Conclusions: The lack of nocturnal blood pressure fall in hypertensive patients is a risk factor of LVH and as well as of sudden cardiac death.
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| 17P-8 EFFICACY OF ANTIARRHYTHMIC AGENTS TO PREVENT PAROXYSMAL ATRIAL FIBRILLATION Prevention of atrial fibrillation using amiodarone, bepridil, or pilsicainide was studied in total of 120 patients with symptomatic paroxysmal atrial fibrillation. Sixty-eight males and 52 females were involved in these subjects with age ranging between 54 to 82 years old. The patients were initially randomized to receive one of the three drugs, according to the left atrial diameter more than 43mm or not, and also with or without organic heart disease. Three months later from randomization, the drug was switched to the others if paroxysmal atrial fibrillation was observed, or the same agent was continued if atrial fibrillation never recognized. In results, prevention of paroxysmal atrial fibrillation was obtained in 29 of 54 patients (53.7%) with amiodarone, 44 of 69 patients (63.7%) with bepridil, and 27 of 60 patients (45.0%) with pilsicainide. There was a significant difference between bepridil and pilsicainide (P = 0.03). The preventive rate with amiodarone (53.3%) or bepridil (51.4%) were significantly superior to pilsicainide (22.2%) (P = 0.002 and 0.03, respectively) in patients with left atrial diameter over 43 mm. There was no significant difference among three agents on factors related with or without organic heart disease. In conclusions, bepridil, as well as amiodarone, was superior to pilsicainide in preventing paroxysmal atrial fibrillation.
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| 17P-9 AUTONOMIC MODULATION FOLLOWING ELECTRICAL CARDIOVERSION OF ATRIAL FIBRILLATION: RELATION WITH EARLY RECURRENCE. Emanuele Bertaglia, Franco Zoppo, Carlo Bonanno*, Nicola Pellizzari, Nicoletta Frigato, Pietro Pascotto. From the Departments of Cardiology, Ospedale Civile, Mirano; *Ospedale S. Bortolo, Vicenza, Italy. Aim. Aims of this study were to to correlate early atrial fibrillation (AF) relapses with heart rate variability (HRV) parameters immediately recorded after electrical cardioversion (EC) of persistent AF. Methods. We performed the spectral analysis of short-term HRV 30 min after EC in 25 patients with persistent AF. Results. The numbers of patients who maintained sinus rhythm at 48 h, seven days, and 30 days were 22, 16, and 14 respectively. A very low low frequency/high frequency ratio [0.93 (0.08) vs 1.89 (1.30); p=0.003] significantly identified patients with AF recurrence at 48 h in comparison to patients without AF recurrence. On the contrary, HRV parameters did not identify patients with AF recurrence at seven or 30 days. Conclusion. AF relapsed within the first 48 h more frequently in patients who presented a predominant vagal tone immediately after the restoration of sinus rhythm.
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| 17P-10 RELATIONSHIP BETWEEN HRT PARAMETERS AFTER ECTOPIC BEATS AND HEART RATE VARIABILITY IN PATIENTS WITH CHD AND DIFFERENT TYPES OF VENTRICULAR ARRHYTHMIAS. Szydlo K., Trusz-Gluza M., Orszulak W., Wita K., Filipecki A., Urbanczyk D. Ist Dept. of Cardiology, Silesian Medical Academy, Katowice, Poland. The purpose of the study was to find out if any links between heart rate turbulence (HRT) and heart rate variability (HRV) might be observed in patients with previous MI and different types of ventricular arrhythmias, when premature atrial (PAC) and ventricular (PVC) contractions were used for HRT calculation. The study population consisted of 80 pts with previous MI with episodes of non-sustained VT (nsVT), sustained VT (sVT) or documented ventricular fibrillation (VF). Patients were divided into two groups. Forty pts without sVT or VF (No VT/VF) (25males, 58±7 yrs, EF-45±7%) and 40 pts with sVT or VF (VT/VF) who underwent ICD implantation (36 males, 57±11 yrs, EF-42±11%). HRT values (TO and TS-turbulence onset and slope) were calculated from the one strip both after PVC and PAC for each patient. HRV parameters (SDRR, rMSSD, LF, HF) were used. Results: values of correlation coefficients are given (for TS): PVC:for SDRR (ms) and RMSSD (ms) No VT/VF: 0.67* and 0.54* VT/VF: 0.52*, 0.41** PAC:for SDRR (ms) and RMSSD (ms) No VT/VF: 0.44* and 0.34** VT/VF: 0.39* and 0.42** *-p=0.01, **-p=0.05 Similar results were obtained for LF and HF. Strong relationships between TS and HRV were observed, especially for PVC. Such a correlations were not present for TO. Moreover, the HRV parameters were remarkable higher in No VT/VF. Conclusion: HRV values differentiated pts with benign and malignant arrhythmias. Strong relationship between these parameters and turbulence slope was found. This may indicate that similar mechanisms are involved in generation of both HRT and HRV.
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| 17P-11 CLINICAL USEFULNESS OF BEPRIDIL IN THE TREATMENT OF ATRIAL FLUTTER Yasuda M, Nakazato Y, Sasaki A, Yamashita H, Kawano Y, Iida Y, Nakazato K, Tokano T, Mineda Y, Sumiyoshi M, Nakata Y, Daida H. Department of Cardiology, Juntendo University School of Medicine, Tokyo and Juntendo Izu-Nagaoka Hospital, Shizuoka, Japan The effects of oral bepridil (Bpd) for atrial flutter (AFL) refractory to class 1 antiarrhythmic drugs were evaluated. Bpd was administered to 50 patients (39 male, mean 63 years old), 30 of which had paroxysmal AFL and 20 of which had persistent AFL. In 20 of 30 patients (66.7%) with paroxysmal AFL, Bpd effectively prevented attacks during an average follow-up period of 18 months. In 16 of 20 patients with persistent AFL (76.2%), AFL was converted into sinus rhythm within an average time of 1.7 months following administration of Bpd. In addition, 15 of those 16 patients have been maintained in sinus rhythm during an average follow-up period of 19 months. ECG revealed prolongation of QT(U) interval from 0.38±0.05 to 0.42±0.05 sec (p
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| 17P-12 ANTI-TACHYCARDIA THERAPY ALTERED MYOCARDIAC GLUCOSE METABOLISM OF THE PATIENTS WITH TACHYCARDIA-INDUCED CARDIOMYOPATHY K Matsumoto, N Takahashi, S Sumita, T Ishikawa, K Matsushita, T Kobayashi, N Kawasaki, Y Yamakawa, K Uchino, T Inoue, K Kimura, S Umemura We assessed left ventricle(LV) function and myocardial glucose metabolism of the patients with tachycardia-induced cardiomyopathy(TC) by using 18F-flurodeoxyglucose(FDG) PET. Forty-two patients with heart disease, consisting of 7 patients with TC(61.6±19.0yrs, LVEF is 41.3±18.4%) and 35 with Ischemic heart disease (IHD)(63.1±10.8yrs, LVEF is 49.9±13.6%). TC was determined as impairment of left ventricular function secondary to chronic or very frequent arrhythmia during more than 10% of the day. IHD patients were revealed significant stenosis by coronary angiography. All of the patients underwent FDG PET and echo-cardiography, and all of the patients with TC underwent FDG PET and echo-cardiography before and 6 months after the anti-tachycardia therapy. As anti-tachycardia therapy, 6 patients were performed radiofreuency catertel ablation and 1 patient was medically treated. We assesse myocardial glucose metabolism semi-quantitatively by using % dose uptake of 60kg of BW (% dose uptake). After anti-tachycardial therapy, LVEF were significantly improved(41.3±18.4% vs 54.3±13.6%, P=0.01), and % dose uptake also significantly improved (1.29±0.35 vs 1.52±0.37,P=0.05). Patients with IHD showed higher value of % dose uptake than TC(2.98±0.82 vs 1.29±0.35, P Evaluating in semi-quntitative analysis of FDG PET, anti-tachycardia therapy altered myocardiac glucose metabolism of the patients with tachycardia-induced cardiomyopathy.
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| 17P-13 INTRAMYOCARDIAL VEGF GENE ADMINISTRATION COMBINED WITH DIFFERENT METHODS OF REVASCULARIZATION IN IHD PATIENTS Eremeeva M., Bokeria L., Golukhova E., Polyakova E., Lukashkin M. For patients with severe myocardial ischemia such interventions as angioplasty or bypass surgery may be required. But a certain group of patients may have no further percutaneous or surgical options. Intramuscular transfection of genes encoding angiogenic cytokines may be alternative strategy for treatment of such group of patients. In our investigation, 16 patients undergoing surgical revascularization received plasmid gene hVEGF 165, injected directly into the heart muscle supplied by coronary artery with distal obstruction. Inclusion criteria: IHD, stable angina III–IV CCS, a significant perfusion defect detected by SPECT and PET. Eligible patients underwent elective CABG, combination CABG + TMLR or TMRL only, but had at least one ischemic territory that was not bypassed due to an unsuitable coronary anatomy. Follow-up was performed in 3 months. Treadmill test and myocardial perfusion imaging were performed before treatment and at 120 days after treatment. All patients reported significant angina relief and improvement quality of life. Patients increased their treadmill exercise times by a mean of 198,8 seconds at the 120-day treadmill compared with baseline testing. Regional wall motion and perfusion were improved, including ungrafted areas with only hVEGF 165 injection.
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| 17P-14 HEART RATE VARIABILITY, INFANTS AND PAROXYSMAL ATRIOVENTRICULAR BLOCK G.Grutter, M.S.Silvetti, A.De Santis, F.Drago Bambino Gesù Hospital, Rome, Italy Purpose of this study is the analysis of the Heart Rate Variability (HRV) in paediatric patients affected by paroxysmal atrio-ventricular block (PAVB). METHODS: PAVB was diagnosed in 9 patients (6 females and 3 males), aged 13+/–4,7 (range 7–21 years)at Holter monitoring. HRV was analysed during 24 hours, at day and night hours, 1 hour, 30 minutes and 1 minute before the longest asystolic pause and were compared with controls. RESULTS: During PAVB, asystolic pauses lasted longer in female patients (3,7+/–0,6 sec) than in males (2,3+/–0,5) (p=000.1). SDNNi and rMSSD values were significantly higher in all patients than in controls; in female patients SDNN was higher than controls (p=000.1). The analysis of HRV before the longest pause showed in all patients a significant reduction of SDNN and SDANN (to zero) and in females also a significant reduction of pNN50 values. CONCLUSIONS: These data seem to confirm the hypothesis of an unbalance of sympatho-vagal modulation on sinus and AV node, as the cause of PAVB.
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| 17P-15 BEHAVIOR OF NONINVASIVE PARAMETERS OF REPOLARISATION IN MYOCARDIAL ISCHEMIA Michal Wasniewski, Romuald Ochotny, Maciej Lesiak, Przemyslaw Mitkowski, Andrzej Cieslinski Methodological problems related to QTd calculation during myocardial ischemia diminishes its clinical utility. Tpeak-end time can represent transmural dispersion of repolarisation. Little is known about its behavior during ischemia. Standard deviation of QT interval (QT-sd) is a statistical control of QT interval variability. Purpose: Comparison of these parameters during ischemia induced by PCI balloon inflation. Methods: 81 patients scheduled for elective PCI (31 LAD, 27 CX and 23 RCA). ECG was recorded (200mm/sec; 40mm/mV) twice: before procedure and in 60th second of first balloon inflation. Results: All parameters increased significantly during ischemia: QTd (51,5+/–15,6 vs 65,9+/–21,0ms), QT-sd (15,8+/–5,0 vs 20,1+/–8,0ms) and Tpeak-end (89,6+/–10,5 vs 104,3+/–12,0ms. Strong positive correlation (tau-Kendall=0,78) between QTd and QT-sd was found. Target coronary artery had no influence on investigated parameters - in each subgroup of patients (LAD vs CX vs RCA) parameters increased during ischemia. Among analyzed parameters only QTd was higher in patients with more advanced coronary artery disease before (III vessel vs I vessel: 66,6+/–13,2 vs 79,3+/–15,9ms) and during ischemia (III vessel vs I vessel: 79,3+/–15,9 vs 59,3+/–18,3ms). Left ventricular mass index had no influence on QTd, QT-sd and Tpeak-end. Significant, negative correlation was found between left ventricular ejection fraction and QTd (tau Kendall =-0,31) and QT-sd (tau Kendall =-0,35). Conclusion: During acute myocardial ischemia Tpeak-end time and QT-sd do not alter more than standard QTd. Relative changes of this parameters and differences in varied subgroup of patients are smaller than QTd.
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| 17P-16 HIGH DOSES OF EBASTINE NORMALISE T WAVE MORPHOLOGY M Malik, K Hnatkova, St. George s Hospital Medical School, London, England Practically all non-sedating antihistamines show changes of cardiac repolarisation ranging from torsade initiation (eg. terfenadine) to clinically insignificant small QT prolongation (eg. loratadine). Recently, the regulators suggested that studies of drug-induced repolarisation changes should include morphological T wave changes that have also been found to predict outcome in cardiac patients. Increased follow-up mortality was found in patients with increased PCA ratio, QRS-T vectorial deviation (TCRT), T wave morphology dispersion (TMD), T loop area, and intra-myocardial repolarisation heterogeneity (the so-called T wave residua - TWR). Repolarisation morphology was studied in digital ECGs obtained in a study of extreme overdose of ebastine, a potent non-sedating antihistamine. Six healthy males (25.5 ± 6.5 y) received single doses of 80, 150, 300, and 500 mg of ebastine (up to 25–50X), and placebo. In each subject, baseline and post-dose ECGs were obtained in each of the 5 phases. Ebastine plasma levels were obtained at corresponding times. QT intervals were measured manually and corrected (QTc) individually. The following correlation coefficients were obtained between ebastine plasma levels and ECG measurements: QTc change vs baseline +0.1200 (NS), PCA ratio -0.1005 (NS), TCRT -0.0485 (NS), T loop area -0.2209 (p=0.0009), TMD -0.1549 (p = 0.0201), TWR -0.2002 (p = 0.0027). Very high doses of ebastine lead to measurable normalisation in the T wave morphology that is consistent with antiarrhythmic rather than proarrhythmic drug effects. This concurs with clinical experience and post-marketing surveillance of the drug which both show that treatment with ebastine does not lead to any proarrhythmic complications.
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| 17P-17 SCREENING OF LEFT VENTRICULAR FUNCTION BY SIGNAL-AVERAGED ELECTROCARDIOGRAM Aihara K, Nakazato Y, Kawano Y, Yasuda M, Nakazato K, Daida H. Department of Cardiology, Juntendo University, Tokyo, Japan. The purpose of this study is to clarify the relationship between left ventricular ejection fraction (LVEF) function and the parameters of signal-averaged electrocardiograms (SAE). Method: We recorded SAE in 162 patients (128 males, average age 62 years), 137 of which were post-myocardial infarction and 25 of which had dilated cardiomyopathy (DCM). The obtained signals were reviewed by time domain analysis. Four parameters including filtered QRS, low amplitude signal duration, total and 40-msec root mean square voltages (TRMS and RMS40) were measured, and the correlation with LVEF was evaluated. Mean LVEF was 0.44±0.18. Results: A significant correlation was observed between the parameters in the time domain analysis and the LVEF. Particularly, TRMS revealed good correlation (r=0.40, p=0.0001). Filtered QRS was significantly longer (p=0.002), and TRMS was significantly lower (p=0.0001) in the group with low EF (<0.35) vs. high EF (>0.35). In low EF group, TRMS was 35.2uV in DCM patients and 59.8uV in post-myocardial infarction patients (p=0.014). Conclusions: The parameters of SAECG correlate with the left ventricular ejection fraction. Particulary, TRMS is a favorable parameter for screening of cardiac function.
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| 17P-18 MAGNETOCARDIOGRAPHIC STUDY OF VENTRICULAR REPOLARIZATION IN RETT SYNDROME Brisinda D*, Meloni AM*, Hayek G^, Calvani M°, Fenici R*. *Catholic University, Rome. ^University of Siena. ° Sigma Tau SpA, Rome. Italy
Rett syndrome (RS) is a genetic disorder predominant in females, with sudden death (SD), thought to be due ventricular repolarization alterations (VRa) and/or of ANS dysfunction. So far for risk-assessment, heart rate variability (HRV), QT duration and its dispersion (QTd) were measured with ECG. However SD has occurred in RS without VRa at ECG. Our aim was to study VRa in RS patients (pts), with magnetocardiography (MCG). Methods: 9 female (age:1–34 years) RS pts (stage II–IV) were studied with an unshielded 36-channels MCG system (sensitivity: 20 fT/Hz1/2,). To assess VRa with MCG, QTpeak, QTend, Tpeak-Tend intervals and QTd, corrected for heart rate (HR), were measured. Moreover ST integral and Tpeak magnetic field (MF) orientation (
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angle), ST dynamics and ST stability were also calculated. 10 age-matched (4–33 years) normal controls (NC) were studied for comparison. HRV time- (TD) and frequency- (FD) domain parameters were evaluated from 24 hours 12-lead Holter ECG. Results: In RS, HR-corrected QTend was longer: 427±16 (RS) vs 412±14 (NC) ms (p<0.05), and QTd was shorter: 18.6±9 (RS) vs 34±10 (NC) ms (p<0.01). STpeak
| 17P-19 THE IMPACT OF CARDIOVERSION SUCCESS ON LONGTERM OUTCOMES IN PATIENTS WITH ATRIAL FIBRILLATION Dhanunjaya R. Lakkireddy, Xuedong D.Shen, Hema L. Korlakunta, Srilaxmi R. Valasareddi, Huagui Li, Syed M. Mohiuddin Creighton University Cardiac Center, Omaha, NE 68131 Background: Atrial fibrillation (AF) is known to be associated with an increased risk of stroke and mortality. It remains uncertain if the success of AF cardioversion affects the long-term outcome of AF patients. Methods: A total of 216 consecutive patients who underwent direct current cardioversion (DC-CV) of AF between 1997–99 were included in this study. They were divided into two groups, Group-I with successful DC-CV on all attempts (71%, 153/216), and Group-II with failed DC-CV at least once (29%, 63/216). Results: Group-I was older (71±9 vs 67±11 years, p=0.008), had a lower body mass index (body mass index >30, 61% vs 37%, p=0.002), a lower prevalence of hypertension (37% vs 60%, p=0.007) than Group-II. There was no statistical difference between the two groups for gender distribution, prevalence of coronary artery disease, cardiomyopathy, diabetes, previous stroke, or echo parameters (left atrial diameter, ejection fraction, spontaneous echo contrast, left atrial appendage emptying velocities). After a mean follow up of 41±12 months, there was no statistical difference between two groups in the incidence of new strokes (3.4% vs 3%, p=ns), death (18% vs 14%, p=ns) and change in ejection fraction (1.3±9% vs -1.5±10%, p=ns). Ninety four percent (144/153) in group-I and 88% (58/66) at the time of final follow up, which was not statistically significant. Conclusion: There was no difference in long-term outcomes between patients who had successful versus failed cardioversion. Therefore strategies of rhythm control by successful cardioversion may not be superior to those of rate control
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| 17P-20 CIRCADIAN AND GENDER VARIATION IN PAROXYSMAL ATRIAL FIBRILLATION Intisar Mirza PhD. John Radcliffe Hospital, Oxford, UK, Amanda Williams Charlie McKenna MD, Battle Hospital, Reading, UK Consecutive twenty-four hour ambulatory ECG recordings from patients referred with palpitations were analysed. None of the patients had prior diagnosis of atrial fibrillation and none were taking anti-arrhythmic medication at the time of recordings. The presence of diurnal and gender variation of paroxysmal atrial fibrillation was analysed with regard the number of hourly episodes recorded over a 24 hour period and related to the time of onset. Statistical comparison was made between number of episodes per 6 hour intervals by the chi-squared test. Gender influence was examined by studying the data from males and females. A total of 22 patients (12 females and 10 males) were included in the study. Results suggested a diurnal variation in the number of episodes with episodes being more frequent during the day with peaks between 11.00 hrs and 18.00 hrs, with relatively lower incidence of episodes at night. The hourly incidence of episodes for male and females suggested an overall greater incidence of paroxysmal atrial fibillation in females throughout the day from 15.00 hrs to 12.00 hrs the next day with peaks of occurrence being recorded between 16.00 hrs and 2100 hrs. There was a significant statistical difference between males and females in the occurrence of episodes when comparing the different time intervals over the 24 hours (Chi- square value 30.6, P value <0.001). This finding may have implications for drug treatment and pharmacokinetics. The higher incidence in females suggests that different neuro-hormonal mechanisms may have a role in the aetiology of this difference.
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| 17P-21 AMIODARONE IN ATRIAL FIBRILLATION RECURRENCE PREVENTION. Kosior D,Stawicki S,Kochanowski J,Scislo P,Roik M,Huczek Z,Opolski G. Dept.of Cardiology, Medical University of Warsaw, Poland, Our prospective study estimate efficacy of sequential AAD therapy in SR maintenance in pts with persistent AF. Methods: 128 pts (61±8 years old) with AF duration 268±99 days underwent elective CV. Following SR restoration pts received one of the following AAD: propafenone, sotalol, disopyramide. In case of AF recurrence we performed second CV and pts received another drug from the mentioned before. If treatment proved to be unsuccessful pts received amiodarone in loading doses and third CV was attempted. Following unsuccessful first CV pts received loading dose of amiodarone and another CV was attempted. In case of SR restoration amiodarone was administered continuously. Results: First CV proved successful in 55.5% pts. Following 1-year 31 pts (43.7%) presented with SR treated with first AAD (median not exist). The second drug proved to be effective in 6 pts (15.0%) (median 13 days). Amiodarone as third AAD, administered to pts who had AF recurrence on first two AAD, proved effective in 18 pts (52.9%) (median not exist) who remained free from AF, for a period of year from the initiation of sequential antiarrhythmic therapy. 57 pts in whom the first CV was ineffective, received amiodarone. During the loading period SR was restored in 7 pts (12.3%). The remaining 50 pts underwent repeated CV and SR was restored in 37 (74.0%) of them. Long-term amiodarone treatment maintained SR in 30 (68.2%) pts. In total, amiodarone helped to maintain SR in 56.5% of pts. Conclusions: sequential AAD therapy improved arrhythmia prognosis within 12-month observation period. Amiodarone seems to be the most effective drug for restoration and maintaining SR in pts with persistent AF resistant to CV and standard antiarrhythmic drug prophylaxis.
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| 17P-22 CHANGES IN HEART RATE AND BLOOD PRESSURE VARIABILITY INDUCED BY SPACE FLIGHT Beckers F, Verheyden B, Aubert AE Dept. of Cardiology, Univ. Hospital Gasthuisberg, KU Leuven, Leuven, Belgium. Introduction: Space flight induces cardiovascular deconditioning. This contributes to the occurrence of orthostatic intolerance after return to Earth. This study was designed to determine alterations of autonomic modulation due to space flight. Heart rate (HRV) and blood pressure variability (BPV) provide a noninvasive means to study the autonomic modulation of the cardiovascular system. Methods: Measurements were performed in 3 astronauts. ECG and continuous BP (finger cuff method) were measured for 10 min. in supine, sitting and standing position 45 days preflight and at 1, 2, 4, 9, 15, 19 and 25 days after return to Earth. In space, ECG and BP were measured at days 5 and 8. Results: In space HR was significantly lower compared to the pre- and postflight measurements in standing position (space: 59 bpm; preflight: 72 bpm; postflight: 102 bpm; all p<0.05). This was accompanied by a significant increase in the proportion of HF power in space (5.7% to 11.1%) and a decrease in LF power (3297 ms^2 to 1251 ms^2). Immediately postflight both LF and HF modulation of HR were extremely depressed compared to the preflight conditions (LF: 3297 ms^2 pre to 546 ms^2 post; HF: 303 ms^2 pre to 38 ms^2 post: all p<0.005). A gradual recovery towards baseline values of both indices was observed up to 25 days after return. In space BPV tended to be lower. BPV was already at preflight levels starting from the first day after return. Conclusion: In space autonomic modulation of HR is characterised by a vagal predominance, while after return to earth overall autonomic modulation is extremely depressed. Recovery of autonomic modulation is slow. Even after 25 days values are not yet at preflight levels. BP modulation seems to be less affected.
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| 17P-23 IMPACT OF CORONARY REVASCULARIZATION ON LONG-TERM CARDIOVASCULAR OUTCOMES OF VF OUT-OF-HOSPITAL CARDIAC ARREST SURVIVORS T. Jared Bunch, Douglas L. Packer, Bernard J. Gersh, Mayo Clinic, Rochester Background: Previous studies reported that the major benefit of revascularization in patients with underlying severe CAD was in primary prevention of sudden death. However the impact of revascularization in OHCA survivors for secondary prevention of sudden death is unclear. Methods: Patients with an OHCA between 1990–2000 who received early defibrillation for VF in Olmsted County Minnesota (MN) were included. Those OHCA survivors with an acute MI or CAD without a MI were further studied. Results: Two hundred patients presented in VF OHCA; of these 138 (69%) survived to hospital admission and 79 (40%) were discharged. The average follow-up was 4.8±3.0 years. Thirty-seven (47%) of the OHCA hospital-discharge survivors presented with an acute MI. Nineteen acute MI patients underwent revascularization (4 CABG, 15 PTCA), and 7 received an ICD and 9 Amiodarone. The observed survival was 17/19 (89%) in those undergoing revascularization versus 9 out of 18 (50%) in the nonrevascularized group (p=0.01). There was no difference in ICD shocks between groups (p=0.19). Twenty-five (32%) hospital discharge survivors presented with CAD without an acute MI. Fifteen underwent revascularization (10 CABG, 5 PTCA), and 12 received an ICD and 3 Amiodarone. There was no significant difference in survival between the groups [13/15 (87%) revascularization, 6 out of 10 (60%) no revascularization, p=0.17] nor ICD shocks (p=0.09). Conclusion: Revascularization after acute MI in VF OHCA survivors improves long-term survival in addition to initial device or drug antiarrhythmic management. This benefit is less prominent in patients presenting with underlying CAD without a MI.
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| 17P-24 LIMITED VALUE OF EP TESTING IN PREDICTING THE CLINICAL OUTCOMES OF VENTRICULAR FIBRILLATION OUT-OF-HOSPITAL CARDIAC ARREST SURVIVORS T. Jared Bunch, Douglas L. Packer, Mayo Clinic, Rochester Background: Patients surviving VF out-of-hospital cardiac arrest (OHCA) remain at high risk of sudden death and variable adverse clinical outcomes. We investigated the usefulness of EP testing for predicting long-term outcomes in terms of survival and quality-of-life (QOL) in OHCA survivors. Methods: All patients with an OHCA between 1990–2000 who received defibrillation for VF in Olmsted County Minnesota (MN) were included. All patients received treatment at one hospital. Long-term outcome and QOL were followed. Results: Two hundred patients presented in VF OHCA, of these 138 (69%) survived to hospital admission and 79 (40%) were discharged. The average age was 62 ± 16 years and length of follow-up was 4.8 ± 3.0 years. EP testing was performed in 48 (61%) patients. An inducible arrhythmia was detected in 28 (58%). EP-guided therapy included ICD placement in 32, ICD with amiodarone in 3, and amiodarone alone in 13. The 5-year risk of an appropriate ICD shock was 26%. Long-term survival of the complete group was 79% with a 92% 5-year survival free of cardiac death. Patients with an inducible ventricular arrhythmia had an increased risk of subsequent ICD shock or cardiac death [HR 3.2 (95% CI 1.0–10.0, p=0.04)]. There was no difference in overall survival if an arrhythmia was induced [HR 0.60 (95% CI 0.19–1.92, p=0.39)]. QOL testing was similar to national controls and equivalent to those without inducible arrhythmias. Conclusion: OHCA survivors are at high risk for sudden death. EP testing in these patients was of limited value in predicting overall long-term mortality or QOL. However, EP-testing identified those OHCA patients at high risk of subsequent ICD shocks and cardiac death.
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| 17P-25 LEFT BUNDLE BRANCH BLOCK IS A PREDICTOR OF VENTRICULAR ARRHYTHMIAS Vieira A, Adragao P, Cavaco D, Reis-Santos K, Morgado F, Abecasis M, Seabra-Gomes R. Hospital Santa Cruz, Portugal Recent ICD studies have shown that patients with left bundle branch block (LBBB) constitute a high risk group. We compared the number of appropriate ICD therapies in patients with structural heart disease, with or without LBBB. Methods: We studied 195 consecutive patients in whom an ICD was implanted (172 men, 61±12 years, follow-up 30±26 months). Every patient included had structural heart disease: 78% coronary heart disease (indication for ICD was primary prevention of SCD in 20%, and secondary prevention in 58%), and 22% idiopathic dilated cardiomyopathy, valvular heart disease and congenital heart disease (secondary prevention indications for ICD). Cardiac resynchronization therapy was coupled with the ICD in 10 patients. Mean left ventricular ejection fraction was 34.7 ±13%. We compared patients with LBBB (69 patients) to those without LBBB (126 patients) with respect to: age, gender, follow-up time, anti-arrhythmic drug therapy, left ventricular ejection fraction, and delivery of appropriate ICD therapy. Results: Demographic characteristics, follow-up time, left ventricular ejection fraction, and anti-arrhythmic drug therapy were similar regardless of the presence of LBBB. Appropriate therapies were delivered by the ICD to 40 patients with LBBB (58%) versus 52 patients without LBBB (41%). The presence of LBBB was significantly associated with the occurrence of appropriate ICD therapies (p=0.03). This association remained significant regardless of the type of indication for ICD implantation (p=0.04 for primary prevention of SCD, and p=0.05 for secondary prevention of SCD). Conclusions: The presence of LBBB identified a group of patients at higher risk for ventricular tachyarrhythmias, requiring ICD therapy.
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| 17P-26 PREVALENCE OF T WAVE ALTERNANS IN TYPE 2 DIABETIC PEOPLE G.Molon, °L.Zenari, *M.Guerriero and E.Barbieri Cardiology - S.Cuore Hospital Negrar Italy; °Diabetology - S.Cuore Hospital Negrar Italy; *Department of Statistics -University of Verona Italy T Wave Alternans (TWA) is a noninvasive prognostic tool for prediction of arrhythmic events in patients with heart disease. Positive TWA (TWA+) is present in 1–2% of healthy people. No data are available in patients with type 2 diabete, a population at high risk of cardiovascular disease. Aim of this study is to verify the prevalence of TWA+ in this type of patients. METHODS: TWA was assessed during bicycle stress test using HearTwave System (Cambridge Heart) in 43 type 2 diabetic volunteers without history of heart disease, with normal ECG and normal exercise test. Mean age was 66±5 years (49–75); males were 35 (77%). RESULTS: Of the 43 volunteers, 2 (4.6%) presented indeterminate test; so we consider for statistic analysis only 41. Sustained TWA at onset heart rate <110 bpm, considered positive TWA, was observed in 9 (21.9%) patients. Maximum Likelihood Estimate of TWA+ prevalence in diabetic population is 0.2195. 95.00% Confidence Interval calculated by Blyth, Still and Casella method is: (0.1167, 0.3742). The analysis show prevalence of TWA+ in this population higher than the prevalence (0.02) in healthy people. Using the "one-sample test of proportions" and calculating with exact methods (because we are working with a little sample) the p-value of the test, we find p < 0.0001, statistically significant. CONCLUSIONS: These preliminary data show a high prevalence of TWA+ in type 2 diabetic patients and seem to confirm the high cardiovascular risk of this population. A larger group of patients with a follow-up is required to better understand the prognostic value and clinical implications of this test with regard to ventricular arrhythmias and total mortality.
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| 24-1 SIMPLE CRYOABLATION WITH A SPECIALLY MADE CRYOPROBE FOR ELIMINATING CHRONIC ATRIAL FIBRILLATION ASSOCIATED WITH MITRAL VALVE DISEASE Hiroshi Tada, Shigeto Naito, Yutaka Hasegawa, Kenji Kurosaki, Masahiko Ezure, Tatsuo Kaneko, Shigeru Oshima, Koichi Taniguchi, Gunma Prefectural Cardiovasc CTR, Maebashi, Akihiko Nogami, Yokohama Rosai Hospital, Yokohama, Japan Background: Recent investigations have indicated that the left atrial (LA) posterior wall of the LA plays a key role in the initiation and sustenance of atrial fibrillation (AF). Methods: Sixty-four patients (pts) undergoing mitral valve replacement were included. In 14 pts, aortic valve replacement was also performed for concomitant aortic valve disease. The mean AF duration was 8.9±9.3 years, and mean LA diameter, 57±10 mm. Cryoablation (-60°C) was applied with a specially made cryoprobe to 4 PV orifices over 2–3 min. The diameter of a spherical tip of the cryoprobe was 2 cm, which is capable of ablating the LA near the PV as well as PV ostium with a single cryoablation. After the cryoablation, mitral valve surgery and a combined surgical procedure were performed. Results: There were no intraoperative complications. Thirty-four pts (53%) with recurrent AF were treated with antiarrhythmic drugs and/or direct current cardioversion. At discharge, 46 pts (72%) had sinus rhythm. During a mean follow-up period of 29±13 months (range, 11–57), 40 pts (63%) had sinus rhythm with (25) or without antiarrhythmic drugs (15). In the pts in sinus rhythm at the end of the follow-up period, the AF duration before the operation was shorter, and the left atrial diameter and cardiothoracic ratio before the operation were less than in patients who were in AF (all for less than 0.001). Conclusion: With a 10–15 minute cryoablation procedure, it was possible to restore and maintain sinus rhythm in 63% of the pts with chronic AF and mitral valve disease.
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| 24-2 CRYOABLATION OF SUPRAVENTRICULAR ARRHYTHMIAS: ACUTE AND LONG TERM RESULTS P. DiDonna, M.Scaglione,D.Caponi, R. Riccardi, M. Bocchiardo, P. Gaetano, L. Vivalda, F. Gaita. Electrophysiology Laboratory. Division of Cardiology, Hospital of Asti, Italy. Aim: Cryoablation has been proposed as alternative energy source since it preserves tissue architecture. We treated several kind of supraventricular arrhythmias in order to verify the feasibility, the safety and the effectiveness in this cohort of patients (pts) Methods: Population consisted of 95 pts (60 males, 35 females, mean age 45±10 yrs) respectively affected by 64 atrioventricular nodal reentrant tachycardia (AVNRT), 24 Wolff Parkinson White (WPW), 11 anteroseptal, 6 midseptal, 5 posteroseptal, 1 right posterior, 1 left posterior, 7 with idiopathic paroxysmal AF (PAF) The AVNRT were ablated targeting the slow potential of the slow pathway. The accessory pathways were eliminated mapping the antegrade conduction during sinus rhythm while in pts with PAF,cryoablation for electrical isolation of pulmonary veins, was guided by basket catheter vein mapping. Results: We achieved the acute success of the procedure in 63/64 of pts (98%) of AVNRT pts, 21/23 (91%) of WPW pts with no complications. Complete PV isolation was obtained in all pts; in 3 pts additional RF applications were required to obtain complete isolation of PV. During a follow-up from 6 to 24 months 8 of 64 AVNRT (12.7%) recurred.One anteroseptal and 2 midseptal WPW recurrence occurred. No AF recurrence was seen in 72% of pts. No PV stenoses were detected. Conclusion: In our study cryoablation demonstrated has been demonstrated to be feasible and safe and it seems to be safer in particular sites (parahissian position and application inside the veins). In PAF pts the end point of the procedure cannot be achieved in all cases using cryoenergy alone
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| 24-3 SAFETY AND EFFICACY OF ATRIAL FLUTTER CRYOABLATION WITH A 9FR, 8MM TIP CRYOCATHETER Annibale S Montenero, F Zumbo, N Bruno, D Mangiameli, A Antonelli, A Ferro, Policlinico MultiMedica, O Murphy, CryoCath Technologies Inc. Introduction: Radio frequency ablation [RF] of the cavotricuspid isthmus to treat atrial flutter [AFL] has a high procedural efficacy but ablation related pain is frequently reported. In this study we examine results from 46 AFL patients (pts) treated with a new 9FR, 8mm tip, and 66mm curve quadripolar (3-5-2) cryoablation catheter Freezor® Max [Max] (CryoCath, Kirkland, Canada) are presented. Method: Cryo ablation was applied in 46 consecutive pts (59.9 + 13.9 years, 34 males), 7 (15.2%) of whom had uncommon AFL. 3 (6.5%) pts had previous RF ablation of AFL. Cryo energy was applied for up to 240s at a mean temperature of –80C. Patient perception of pain on cryo energy delivery was continually monitored and recorded throughout the procedure. Acute efficacy was defined as the presence of bi-directional isthmus conduction block [BDB] 30 min after ablation. Results: Acute success was achieved in 44 (95.7%) of 46 pts. Furthermore, BDB was achieved in all 39 (100%) common AFL pts and 3 (100%) pts who had previous RF ablation for AFl. The mean number of cryo ablations was 4.2 ± 3.5. Mean ± SD procedure duration and fluoroscopy time were 78.0 ± 54.1 mins and 17.5 ± 25.4 mins respectively. There were no complications in any of the 46 pts and of special note; all pts remained completely discomfort free during cryo energy delivery. Conclusion: The acute success, procedure duration and number of cryo ablations are much improved compared with Xtra catheter results and comparable with RF for AFL ablation. Our ability to ablate AFl with Max is as effective as RF but with the added benefit of zero patient discomfort during cryo energy delivery, ablation with Max is our first choice for treating AFL.
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| 24-4 CRYOTHERAPY ABLATION OF ATRIAL FLUTTER:LONG TERM FOLLOW-UP IN A LARGE SERIES OF PATIENTS Annibale S. Montenero, Nicola Bruno, Francesco Zumbo, Daniele Mangiameli, Andrea Antonelli, Cardiology Dept. and Arrhythmia Center, Multimedica General Hospital, Milan, Italy and Olive Murphy, CryoCath Technologies Inc, Kirkland, Canada Introduction: Atrial flutter [AFl] ablation represents one of the major challenges in electrophysiology [EP].Cryo ablation [CAbl] in EP has increased in recent years, however there are no reported long-term results for a large series of patients (pts) who have received CAbl for AFl. Method: 158 consecutive pts received cryoablation for AFl at our centre. All pts kept a diary record of symptoms experienced following the cryo ablation procedure. These records are collected at our out-patient clinic every month for two years. Regardless of symptom recurrence, a follow-up (f-up) invasive EP study (EPS) was performed on all consenting pts at approximately 3 months post cryoablation. If symptoms of AFl were reported prior to the 3-month follow-up time, an invasive EPS was carried out immediately in order to determine if conduction across the cavotricuspid isthmus (CTI) had recurred. Results: CTI block was achieved acutely in 142 (90%) of 158 pts. 137 (97%) of 142 pts remain free of symptoms of AFl to date. 69 pts consented to a f-up EPS even though they had no symptoms of AFl. This invasive EPS was conducted at mean ± SD 123 ± 84 days following CAbl. 26 (38%) pts had conduction recurrence across the CTI, but did not have symptoms of AFl. These pts received further CAbl to restore bi-directional isthmus block. Conclusion: Our long term results are promising with 97% of pts remaining free of AFl symptoms. It should be noted that pts with recurrence of conduction across CTI did not have symptoms of AFl. CAbl of AFl is a safe and effective long term treatment for symptomatic AFl pts.
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| 24-5 CIRCUMFERENTIAL CRYOISOLATION OF PULMONARY VEINS: ACUTE RESULTS AND CLINICAL FOLLOW-UP Single pulse isolation of pulmonary veins (PV) is associated with reconducting muscle sleeves and the risk of PV stenoses particularly with radiofrequency technique (RF). We report on circumferential PV isolation with the new Arctic Circler (AC) (Cryocath, Canada). Guided by a 20-pole Lasso catheter, proximal PV Isolation was performed using the self-expanding AC with a maximum diameter of 30 mm over 4 min of cryoimpulses (CI) at a temperature of -75°C to -90°C (with N20). Electrical gaps were closed using a 6-mm tip cryocatheter. Out of 37 patients (P) (26 men, age 58±8 years, refractory to antiarrhythmic therapy, 34 with paroxysmal, 3 with persistent atrial fibrillation (AF)) 24 were treated in a first attempt, 13 after ablation 3 months ago because of AF recurrence. Out of 133 PV 15 were isolated with the 6-mm tip cryocatheter because of small diameter or few inputs only. 118 PV were isolated with the AC alone in 53% (63 PV), with additional gap closing in 47% (55 PV) (Table). After 5.5±2.5 months 7 of 17 P had no recurrence, 7 P had a marked reduction of AF burden, that is a significant clinical improvement of 82%. Circumferential PV isolation with CI is highly effective, In comparison with RF, no PV stenoses develop and less myocardial sleeves show reconduction.
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| 24-6 INCIDENCE OF PULMONARY VEIN STENOSIS AFTER CATHETER CRYOABLATION Neumann T*, Greiss H, Erdogan A*, Berkowitsch A, Kurzidim K, Sperzel J, Pitschner HF Kerckhoff - Clinic Bad Nauheim, Germany Justus-Liebig-University Gießen, Germany* Introduction: The acquired pulmonary vein stenosis (PVS) after pulmonary vein isolation (PVI) using radiofrequency energy applications is a well-known complication of this procedure. The objective of this prospective clinical study was to evaluate the incidence of PVS after catheter cryoablation. Methods: In 26 patients (pts) (age 53±11years, 15m) with symptomatic paroxysmal atrial fibrillation we performed a pulmonary vein isolation. For the ablation procedure we used the CCT.2 Cryo ConsoleTM (CryoCath) and the Artic Circler curvilinearTM CryoAblation Catheter from the same company. The acute success rate of each PVI was verified by the evidence of an entrance- and exit-block using a 10-polar LassoTM catheter (Biosense Webster). The diameter of each pulmonary vein (PV) were measured before, one day after the ablation procedure and every further three months using MR angiography. Results: In 10/26 pts all PVs were completely isolated. In total 71/104 of the treated PV's we performed a successful isolation. The mean time of cryoablation for PVI was 1571 (lateral upper PV), 1026 (lateral lower PV), 1241 (septal upper PV) and 917 (septal lower PV) seconds. In 7 pts the ablation catheter couldn't placed in the septal lower PV. After median follow-up of 7.7 months no pulmonary vein diameter reductions, defined as a luminal narrowing >25% of the original diameter, were observed. In one pt we find a severe PV stenosis (80%) of the lateral upper PV 7 months after a second ablation procedure using radiofrequency energy. Conclusions: The catheter cryo ablation of the pulmonary veins seems to be a safe ablation strategy concerning the incidence of pulmonary vein stenosis.
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| 26-1 EFFECT OF DAILY ACTIVITIES ON PROGNOSTIC VALUE OF HEART RATE VARIABILITY Dabrowski A, Kubik L, Kramarz E, Zachorski M. Institute of Military Medicine,Poland, Warsaw Background. Clinical studies have been shown that short-term analysis of heart rate variability (HRV) may be an efficient method for risk stratification in patients after myocardial infarction. The aim of this study was to assess the impact of normal daily activities on the prognostic significance of short-term measures of HRV. Methods. In the group of 178 postinfarction patients the analysis of HRV was performed in 5-minute ECG segments recorded from 3 time periods: at night, during daily rest and during habitual physical activity. For the purpose of this study, 4 different HRV indices were measured: 1 SDNN -, 2 rMSSD -, 3 LH -, 4 HF -. Using univariate and multivariate Cox regression analyses the relation between values of HRV variables and total mortality was assessed. Results. During follow-up of 41±18 months, 46 patients died. At daily rest reduced values of all HRV variables had significant association with occurrence of deaths. On the contrary, variables of HRV measured from ECG recording at the time of physical activity did not predict deaths during follow-up. Among the four HRV variables assessed during varied daily activities the reduced low-frequency power during night-time, adjusted for left ventricular ejection fraction, gender and age of evaluated patients was the best predictor of total mortality (hazard ratio 3.12, 95% confidence interval 1.7–5.9; p= 0.0004). Conclusion. Prognostic significance of short-term HRV analysis is related to type of daily activities during ECG recording. This relation should be considered in selecting ECG segments for short-term HRV analysis.
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| 26-2 REINNERVATION OF THE DONOR HEART AFTER HEART TRANSPLANTATION Beckers F, Ramaekers D, Speijer G, Ector H, Vanhaecke J, Verheyden B, Van Cleemput J, Droogné W, Van de Werf F, Aubert AE Dept. of Cardiology, Univ. Hospital Gasthuisberg, K.U. Leuven, Leuven, Belgium. Background: In humans, the occurrence of reinnervation of the donor heart after heart transplantation remains controversial. Methods: A total of 1007 Holter recordings of 245 heart transplant patients were retrieved from the hospital archives spanning a period of 10 years. The average age of the patients was 56 yrs at the time of the last recording. In 144 patients 3 or more consecutive recordings were available (average 4.5+/–1.1 recordings). All patients were on immunosuppressive therapy, consisting of azathioprine, cyclosporine and methylprednisolon. Heart rate variability (HRV) was used to assess the evolution in autonomic modulation and as such, possible signs of functional reinnervation. Results: HRV analysis of all data (not separated into different subgroups) revealed an increase in 24-hour total power starting from 2 years after transplantation, up to 9 years compared to recordings in the first year after transplantation (year 2: p<0.05, year 3–8: p<0.001, year 9: p<0.05; Tukey's post-hoc analysis). 24-hour low frequency (LF) power started to increase significantly from year 3 up to year 8 compared to the early recordings (all p < 0.001 compared to year 0). Day and night LF power showed an increase starting at 4 years after transplantation. High frequency power did not show a significant evolution over the first 10 years after transplantation. Sub-group analysis proved that only about 6% of the patients showed clear signs of reinnervation. Conclusion: The vast majority of the patients remain functionally denervated up to 10 years after heart transplantation. However some patients show signs of reinnervation after heart transplantation.
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| 26-3 LAD GRAFTING: VENOUS, ARTERIAL OR NONE - SHORT AND LONG TERM HRV ANALYSIS AFTER SURGERY Orszulak W., Trusz-Gluza M., Giec L., Bochenek A., Myszor J. Silesian Medical University, Silesian Heart Center, Katowice, Poland The prospective study assessing HRV parameters in patients undergoing CABG made possible to evaluate the role and type of LAD grafting. The study population consisted of n 62 males, age 54±10 years with mean LVEF 49±17% (43 pts were post MI). Time and frequency parameters of HRV were defined before, 2–6 weeks and 1 year after CABG. Arterial grafting (LIMA) in 22 pts and venous grafts in 35 pts were performed. LAD grafting was not done in 5 pts due to the lack of technical possibility. All HRV parameters were reduced in pts without LAD graft: SDNN, SD, rMMSD were significantly lower (61±13 vs 82±29ms, p<0,05; 21±4.5 vs 30±11ms, p<0,01; 13±3,3 vs 17±5,2ms, p<0,05); as well as LF, HF, TP (60±30 vs 136±138ms2, p<0,01; 17±11 vs 37±30ms2, p<0,05; 192±93 vs 404±311ms2, p<0,01) in the early postoperative period. No impact of LAD grafting on HRV values was found one year after CABG. The changes in HRV parameters were not depended on the type of LAD grafting 2–6 weeks after CABG (venous or arterial). The HRV parameters were similar to preoperative values one year after CABG in pts where LIMA was used. In opposite, in pts with venous LAD grafting some HRV parameters were still significantly lower (SD 45±16 vs 51±18ms, p<0,05; LF 328±333 vs 427±394ms2, p<0,05; HF 94±98 vs 123±118ms2, p<0,05; TP 917±770 vs 1222±966ms2 p<0,05). Conclusion: Incomplete revascularization (lack of LAD grafting) during CABG induces an important reduction in HRV parameters. It may be a significant risk factor in the early postoperative period. HRV parameters changes observed one year after CABG suggest the advantage of using LIMA in LAD grafting.
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| 26-4 HORMONE REPLACEMENT THERAPY DOES NOT MODIFY HEART RATE VARIABILITY Eney O. Fernandes, Ruy S. Moraes, Maria Celeste O. Wender, Elton Ferlin, Jorge P. Ribeiro. Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul. Porto Alegre-RS, Brazil BACKGROUND: Postmenopausal women are at greater risk of coronary heart disease. Observational studies have demonstrated that hormone replacement therapy (HRT) improves lipid profile and cardiac autonomic modulation. The cardioprotective effect attributed to HRT has not been tested in randomized, placebo-controlled trials to compare the two most frequently used regimens. OBJECTIVES: This study evaluates cardiac autonomic modulation in postmenopausal women using time domain indices of heart rate variability (HRV) and indices derived from the three-dimensional return map, and investigates whether continuous HRT for three months, either with estradiol alone (ERT) or with estradiol and norethisterone (HRT), increases HRV in postmenopausal women. METHODS: Forty postmenopausal women aged 46 to 63 years were consecutively and randomly assigned to one of three treatment groups: HRT, ERT, or placebo. For all women, clinical, gynecological and laboratory data were collected. Women underwent 24-h ECG before and after the treatment to evaluate HRV indices. RESULTS: Time domain indices of HRV as well as indices derived from the three-dimensional return map presented no significant changes after interventions. The augmentation seen in estradiol values was not associated with HRV indices. The only significant difference between HRT and ERT groups was in lipid profile. HDL cholesterol levels decreased 12.4% (p = 0.008) for women who used HRT. CONCLUSION: In postmenopausal women, continuous hormone replacement therapy with estradiol or estradiol with norethisterone for three months does not affect cardiac autonomic modulation evaluated by HRV.
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| 26-5 COURSE OF CARDIAC PARASYMPATHETIC REFLEX CONTROL FROM THE SUBACUTE TO THE CHRONIC PHASE OF MYOCARDIAL INFARCTION Ortak J, Wiegand UKH, Bode F, Richardt G, Bonnemeier H. Medical Clinic II, University Luebeck, Germany. Depressed parasympathetic tone directed to the heart is associated with electrical instability and adverse outcome after myocardial infarction (MI). Both, heart rate turbulence (HRT), reflecting reflex vagal activity, and heart rate variability (HRV), reflecting tonic vagal activity have been shown to be reduced in the subacute phase of MI. However, the course of each of these components of cardiac vagal control from the subacute to the chronic phase of MI has not yet been defined. Methods and Results: We therefore investigated 100 consecutive patients (79 male, 21 female, 56.7±8 years of age with a first MI. HRT and HRV were determined from 24-hour-Holter-recordings ten days and twelve month after the index MI. There were no significant differences in mean RR-interval in the subacute and chronic phase of MI. Parameters of HRV (SDNN, SDNNi, SDANN, rMSSD, TI) significantly increased within the observation period, whereas there were no significant alterations of parameters of HRT (Turbulence Onset, Turbulence Slope).
Conclusion: In contrast to reflex vagal activity, there is a significant recovery of tonic vagal activity within 12 month after MI. These findings indicate different patterns of regeneration of reflex and tonic cardiac vagal control after MI, which has to be considered using these parameters for risk stratification in patients with ischemic heart disease.
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| 26-6 ARRHYTHMIA RISK PREDICTION IN IDIOPATH1C DILATED CARDIOMYOPATHY BASED ON HEART RATE VARIABILITY AND BAROREFLEX SENSITIVITY W. Grimm, J. Sharkova, M. Christ, and B. Maisch Department of Cardiology, Philipps-University Marburg, Germany. The Marburg Cardiomyopathy study prospectively investigated the clinical value of heart rate variability (HRV) on 24 hour Holter ECG and baroreflex sensitivity (BRS) using the phenylephrine method in 263 patients with idiopathic dilated cardiomyopamy. Predefined measure of HRV was the SD of all normal-to-normal intervals on Holter (SDNN). During 52±21 months follow-up, major arrhythmic events defined as sustained VT, VF or sudden death occurred in 38 study patients (14%).
Conclusions: In contrast So LV ejection fraction, heart rate variability and baroreflex sensitivity were not found to be helpful for arrhythmia risk stratification in idiopathic dilated cardiomyopathy. These findings have important implications for the design of future studies evaluating the role of prophylactic ICD therapy in idiopathic dilated cardiomyopathy.
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| 29-1 AUTOMATIC IDENTIFICATION OF CLINICAL LEAD PROBLEMS BD Gunderson, MS, AS Patel, MS, CA Bounds, BSEE, KA Ellenbogen*, MD, Medtronic, Inc., Minneapolis, MN, *Medical College of Virginia, Richmond, VA Introduction: ICD lead problems can cause inappropriate shocks. Current and future devices contain increased memory for storage of lead diagnostics and automatic triggered episodes. These stored diagnostics and episodes with intracardiac ventricular electrograms (EGM) and sensed RR interval patterns characterize ICD lead performance. Purpose: The goal of this analysis was to determine the sensitivity (S) and positive predictive value (PPV) of an automatic lead problem identification algorithm. Methods: The algorithm uses RR and EGM data to identify non-cardiac oversensing (OS) problems (e.g. conductor fracture, EMI) and cardiac OS problems (e.g. T-wave OS) from other detected episodes. Also, the algorithm uses lead diagnostics: Sensing Integrity Counter (e.g. RR<140 ms), non-sustained episodes with a mean RR < 200 ms and impedance trends to identify lead failures (e.g. conductor fracture). The PPV was determined using the stored memory from 1,756 ICD patients (pts) enrolled in a 13 center chronic lead study with an average follow-up of 18.3 pt-months. The S was determined using 35 of these pts (26 lead failure, 7 T-wave OS, 2 EMI) with an OS or lead failure adverse event and confirmed with stored ICD diagnostics. Results: The algorithm S was 97.1% (34/35). There were an additional 43 pts identified by the algorithm without an adverse event. Stored ICD diagnostics confirmed 32 of the 43 pts with lead problems. The PPV was 85.7% (66/77). Conclusion: ICD memory diagnostics and episodes with intracardiac EGM may be used to identify ICD lead problems with high S and PPV. This algorithm may be implemented in post-processing ICD environments (i.e. remote server, programmer) to quickly identify lead problems.
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| 29-2 ANALYSIS OF ATRIAL PACING IMPEDANCE VARIATIONS USING AN ISOLATED HEART MODEL Timothy G Laske, Alex J Hill, Nicholas D Skadsberg, Sarah A Vincent, Paul A Iaizzo, University of Minnesota, Minneapolis, MN, USA, Medtronic Inc., Minneapolis, MN, USA Introduction: Variations in atrial pacing impedances at implantation are commonly seen. This study aims to recreate clinical situations that result in unusually high pacing impedances in order to provide insight into the clinical consequence of these situations. Methods: Five porcine hearts were reanimated and perfused on an isolated heart apparatus (the Visible Heart®) with a modified Krebs perfusate allowing for direct, intracardiac visualization. A videoendoscope was used to record intra-atrial behavior while recording pacing performance parameters. A fixed screw, bipolar pacing lead was implanted in the atrium using an endocardial approach (N=24 across the 5 isolated hearts). Pacing performance parameters (impedance, P-wave amplitude, and pacing threshold) were recorded for the following situations: 1) lead free in atrium, 2) helix contacting tissue, 3) helix 1 turn fixed, 4) helix fully fixed (2 turns), 5) lead body overtorqued 1 turn, and 6) lead body overtorqued 2 turns. Results: Excessive torque applied to the lead resulted in two situations: 1) tissue partially wrapping around the tip of the lead, producing higher than expected pacing impedances (N=12; impedances of up to 1463 ohms) or 2) damage to the tissue at the electrode interface ("cored" tissue) with relatively stable impedances (N=12). The changes in lead impedance were significant for the helix 1 turn fixed (p=0.04) and 2 turns overtorqued (p=0.001) vs. fully fixed. Conclusions: Excessive torque applied to active fixation pacing leads can produce higher than expected pacing impedances and can damage atrial tissue.
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| 29-3 ACUTE EFFECTS OF INTERNAL SHOCK DELIVERY ON LEAD PARAMETERS IN ICD-PATIENTS Michaelsen J, Becker R, Voss F, Weretka S, Schoels W. University Hospital, Internal Medicine III, Heidelberg, Germany Background: A significant rise in lead threshold after external shock application (electrical cardioversion e.g.) is casuistically described in patients with an internal pacemaker. We therefore prospectively investigated the lead behavior concerning multiple parameters in ICD patients after internal shock application. Methods: At the routine pre-hospital discharge test in 44 consecutive ICD patients (41 male, age 63 ± 11 years) after implantation of a new ICD system data concerning lead impedance, sub-threshold shock lead impedance, pacing threshold and ventricular sensing were measured 1, 5 and 10 minutes after internal shock application respectively. Ventricular fibrillation was induced with a T-wave shock of 0.6 J. Results: After internal shock delivery (16 ± 3 J) no significant changes were seen concerning pacing threshold. Ventricular sensing showed non significant lower values down to 50% of initial values (p=0.25). We found a significant decrease in pacing lead impedance with a trend to normalize 10 minutes after shock delivery (-31 ± 81 Ohm after 1 minute, -12 ± 47 Ohm after 10 minutes, p<0.05). A decrease in sub-threshold shock lead impedance was unsignificant (p=0.3). In 1 patient a dramatic rise of the shock lead impedance was found 10 minutes after shock delivery (27 up to 134 Ohm), all other parameters were found to be normal. After 2 months of frequent follow-ups this patient had to undergo shock-lead revision due to documented lead fracture. Conclusion: Nominal ICD-settings allow safe and reliable ICD-function after internal shock-delivery; a slight decrease of the sub-threshold shock-coil-impedance after internal shock delivery seems normal, further changes may point on possible lead problems.
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| 29-4 PACEMAKER LEAD DESIGNS ON RADIO FREQUENCY HEATING IN MRI BY FINITE ELEMENT ANALYSIS Xiaoyi Min, Gene Bornzin, *Ariel Roguin, *Menekham M. Zviman, *Henry R. Halperin, St. Jude Medical, Sylmar, CA, *Johns Hopkins University RF energy coupled to a Pacemaker lead during MRI can cause excessive tissue heating near the tip electrode. In-vitro studies have showed that different leads resulted in different temperature rises (dT), but the underlying mechanisms are unclear. We investigated the effect in the distal designs of passive and active leads on dT. Method and Results: In-vitro tests in a saline tank showed that dT with a bipolar coaxial passive lead (1346T/46 cm, St. Jude Medical) was less than half with a bipolar coaxial active screw lead (1488T/46 cm, St. Jude Medical) i.e. 1.4 TC vs. 3.5 TC (helix retraction) or 5.3 TC (helix extension). To understand the difference in dT, Finite Element (FE) models were created with a saline tank inside a RF birdcage coil of a 64 MHz 1.5T MRI. Both bipolar leads only differ in the distal portion. FE results showed that most current were around the tip and the ring having an order of magnitude higher than in the conductors underneath the insulation. Maximum specific absorption rate near the tip was used to estimate dT. For RF pulsing duration of 1.8 ms, dT in the models was 1.7 TC for the 1346T lead and 4.0 TC (helix retraction) and 5.5 TC (helix extension) for the 1488T lead. Higher dT on 1488 lead was due to that the helix and the mapping electrode on it created higher local electrical fields compared to the hemisphere tip on 1346T lead. Less energy dissipation and more convection around ring electrodes makes heating nearby less of a concern. Conclusions: FE model results are consistent with the in-vitro measurements. Electrode tip design can have a major impact on RF heating.
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| 29-5 SALVAGE OF LEAD FROZEN IN HEADER BY BONE CUTTER, DRILL OR SAW John D. Fisher, Peter Lapman, Soo G. Kim, Kevin J. Ferrick, Jay N. Gross, Eugen C. Palma, Alexander DelVecchio Montefiore Medical Center-Albert Einstein College of Medicine, Bronx NY, USA Purpose: Some leads prove difficult to disconnect from headers at the time of pulse generator replacement without injuring the fragile leads. In two years we encountered this problem five times (<1.5%). We aimed to test the effectiveness of a bone cutter, drill, and saws for lead salvage. Methods: Clinical Cases: The back of the header was clipped off at the deep end of the lead socket using a Stille-Liston orthopedic bone cutter in 4 cases (the 5th was not attempted). A metal rod was then used to push the lead out of the socket. Bench testing of several methods was done on 10 previously explanted pulse generators held in a vice. Different header sites allowed testing of all methods. In addition to a bone cutter, motorized tools were used to drill holes from the end of the header to the deep end of the socket; or with a rotary saw attachment to slice off the back of the header. The latter was also done with a hand-held razor saw. Results: Lead removal in the clinical cases was quick and easy in all cases using the bone-cutter, without trauma to the lead. Bench testing results varied. The bone cutter was the most efficient for most brands, but one header was too tough. The motorized tool was difficult to position, produced plastic particle sprays, and would risky for the clinical operator. The razor saw was difficult to use safely or efficiently, except in some headers that resisted the bone cutter. Conclusion: An orthopedic bone cutter is a useful tool for removing a retained lead from a pulse generator header. Differences in header design and materials necessitate knowledge of several lead detachment methods.
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| 33-1 DIFFERENT BAROREFLEX CONTROL DURING THORACIC AND ABDOMINAL RESPIRATION Vladimir Tuka, Jana Rotreklova, Jan Molinsky, Jan Malik, Jan Simek, Dan Wichterle General University Hospital, Prague, Czech Republic Background: Abnormalities in baroreflex function have been linked to adverse cardiovascular outcomes. Respiration itself (independent of blood pressure changes) may interact with arterial baroreflex in short-term cardiovascular autonomic control. Methods: This study investigated 12 healthy volunteers (6 women, aged 23 ± 1 years). Each subject underwent two 3-min consecutive sessions of thoracic and abdominal respiration in random order. During both sessions, controlled respiration at 0.1 Hz was paced by visual signals and flowmetry was used for feedback control to keep constant tidal volume. ECG and finger arterial pressure recordings were obtained. Heart rate and systolic blood pressure (SBP) variability, and baroreflex gain (BRS) were established by spectral and cross-spectral analysis in low-frequency band. Results: Despite the same respiratory frequency and tidal volume, there were significantly higher heart rate variability, enhanced baroreflex gain, and the trend to reduced SBP variability during thoracic compared to abdominal respiration
Difference in baroreflex gain was independent of prevailing heart rate. Conclusion: Thoracic respiration is associated with more effective baroreflex control compared to abdominal respiration probably due to different involvement of stretch receptors in thoracic aorta, lung or left ventricular mechanoreceptors. This finding is of potential clinical value as the training of thoracic respiration might improve prognosis of patients with cardiovascular diseases.
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| 33-2 AUTONOMIC FUNCTION IN SYNCOPE PATIENTS Verheyden B, Beckers F, Reybrouck T, Ector H, Aubert AE Dept. of Cardiology, Univ. Hospital Gasthuisberg, K.U.Leuven, Leuven, Belgium Purpose. The purpose of this study is to evaluate the underlying mechanism of vasovagal syncope (VVS) using indices of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS). Methods. 23 subjects consisting of a control group (N=10, aged 23±5 yrs), a patient group (N=10, aged 38±9 yrs) and a training group (N=8, aged 33±5 yrs) performed the Westminster tilt test protocol (HUT). The training group consisted of VVS-patients that were enrolled in a tilt-training program (between 3 and 12 sessions). The tilt test was positive in 3 subjects from the training group and in all subjects of the patient group. Continuous ECG and blood pressure were recorded simultaneously. Low frequency (LF: 0.04–0.15 Hz) and high frequency (HF: 0.16–0.4 Hz) powers in heart rate and blood pressure were calculatedduring HUT. Baroreflex gain was assessed using the sequence method. Results. Both HF and LF powers of HRV were higher in the control group compared to the patient group (respectively 1415 ms2 vs. 1024 ms2 and 1405 ms2 vs. 714 ms2). In the control group, LF power of BPV was increased by 60% at the start of HUT compared to supine rest whereas in the patient group LF power of BPV remained unchanged. The gain of the cardiac baroreflex mechanism tended to be higher at supine rest in the control group compared to the patient group (19 vs. 8 ms/mmHg) and decreased significantly after tilt only in the control group by 68%. BRS in the training group tended to increase (NS) with increasing tilt sessions. Conclusion. Cardiac autonomic control and vasomotor sympathetic reflex activity is suggested to be impaired in VVS-patients. Tilt training showed a general reconditioning of dynamic cardiovascular regulation in VVS-patients.
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| 33-3 ATP TEST IN SYNCOPE OF UNKNOWN ORIGIN. PRELIMINARY RESULTS OF A MULTICENTER STUDY D. Flammang on behalf of the ATP Study Group Vasovagal manifestations are related to the nature and the severity of the underlying mechanism. Head-up tilt test reproduces mostly vasodepressive symptoms but the strong vagal action of ATP has been reported to be able to identify patients (pts) with syncope (S) due to a potential long cardiac pause. ATP test (20 mg I.V. bolus) is considered + when the drug provokes a cardiac pause > 10 sec. whatever the associated symptoms; its positivity is clearly related to pt age and a permanent pacing improves significantly the follow-up. Objective. This prospective study aims to verify that pts with pre-S or S of unknown origin and a + ATP test will benefit from a DDD pacemaker (PM) implantation. Methods. 20 centers participate in this trial. Inclusion criterion was a S of unknown origin and a + ATP test, whatever the HUT results; main exclusion criterion was a + carotid massage. Eligible pts who accepted implantation were randomly assigned to AAI 30 bpm or DDD70 bpm pacing mode and symptoms recurrence was examined in both groups during 24 months. Results at 30% of the inclusion period. From January 2000, PM was implanted in 60 + ATP test pts (11% of tested pts); among the 30 pts in AAI mode, 10 experienced recurrence at month 2 (3 pts), 6 (2 pts), 12 (4 pts) 24 (1 pt) vs only 3 pts in DDD mode at month 2. Ten pts completed the 24 months follow-up. Mean age was 75.2 (48–91) years old and 80% of them were women. Conclusions. ATP test is able to identify pts with S due to a severe cardio-inhibitory reflex of vagal origin and to provide arguments for a permanent pacing therapy. This study will also determine the influence of age, sex, and cardiac diseases on the test results and position it in the screening of vasovagal patients.
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| 33-4 A SINGLE CENTER EXPERIENCE WITH IMPLANTABLE LOOP RECORDERS IN THE PEDIATRIC POPULATION TR Betts, A Yue, J Paisey, PR Roberts, JM Morgan. Southampton University Hospitals, UK Background: Use of the implantable loop recorder (ILR) has been widely reported in the adult population. The utility of these devices in the pediatric population is less well known. Methods: A retrospective analysis was performed of patients (pts) <18 years of age receiving an ILR (Reveal, Medtronic Inc) at a single institution between March 1998 and November 2003. Results: A total of 26 pts (18 male, mean age 13.0±4.5 years, range 8 months-18.0 years) received ILRs. 4 pts had congenital heart disease. 5 pts had suspected or confirmed Long QT syndrome. Symptoms were syncope (15), pre-syncope (2), palpitations (8) and asymptomatic (2). No pt suffered complications from the device implant. 2 pts failed to manually activate recordings on one occasion. 17 pts had symptomatic episodes with automatic or manually activated recordings that resulted in the diagnosis or exclusion of a cardiac cause. The mean time to appropriate activation was 104±91 days (range 15–360 days). Recorded rhythms in these 17 pts were sinus rhythm/tachycardia (6), bradycardia consistent with neurocardiogenic syncope (4), asystole (1), ventricular ectopy (1) and supraventricular tachycardia (5). One pt with a permanent pacemaker had ventricular fibrillation that was not detected by the device. No events or activations occurred in the 2 asymptomatic patients. The remaining 6 pts with symptoms prior to implant and no automatic or manual activations had no recurrence of their symptoms during a mean follow-up of 380±312 days (range 18–981). Conclusions: ILRs in the pediatric population are safe and have a relatively high diagnostic yield. In rare circumstances, manual and automatic activation of the recorder may fail.
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| 33-5 COST EFFICACY OF IMPLANTABLE RECORDER IN UNEXPLAINED SYNCOPE JM Morgan, DL Chase, SJ Earles, JR Paisey, AM Yue, TR Betts, F Luland PR Roberts, P Roderick Objective: To assess the procedural costs, diagnostic yield and cost efficacy of two syncope investigation strategies: implantable loop recorders (ILR) and Electrophysiological studies (EPS)±ILR. Methods: A single centre randomized controlled trial of individuals with 2 or more syncopal episodes in the previous 12 months, structurally normal hearts, negative tilt table tests and Holter recordings. Patients were randomised to either ILR or EPS±ILR (those allocated EPS were offered ILR after 6 months if they remained symptomatic after negative EPS). Positive diagnosis was defined as a sustained cardiac arrhythmia monitored and correlated to symptoms or detection of corrected sinus node recovery time over 550 msec or a His-Ventricle (HV) interval over 75 msec or induction of a sustained tachyarrhythmia. Procedural costs of the two strategies were compared by routine investigations performed. On completion of follow up complete syncope related healthcare resource utilization will also be compared between strategies. Results: 59 patients consented, 9 withdrew and 1 died pre procedure. 49 patients received either EPS or ILR, of these 6 withdrew, 2 died and 1 was excluded for a protocol violation. 37 patients aged 18–83, 26 of which are female have completed, 3 remain under follow up. Of the EPS group 11 were eligible to cross over for ILR and 10 crossed over. 8 arrhythmia diagnoses were made in the ILR strategy and 2 in the EPS±ILR strategy after medians of 118.5 and 169 days respectively. The procedural costs of the strategies were £1820 in the ILR group and £2310 in the EPS±ILR group. Conclusions: The ILR strategy offers lower procedural cost than the ILR±EPS strategy. This points to the likelihood of a better overall cost efficacy.
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| 33-6 DIAGNOSIS OF SYNCOPE WITH THE IMPLANTABLE LOOP RECORDER: CLINICAL VALUE OF AUTOMATIC RECORDING FEATURES C. Ehlers, J. Ücer, M. Wiedemann, D. Andresen Vivantes Urban Hospital, Arrhythmia Center, Berlin, Germany Background: The implantable loop recorder (ILR) is an effective tool in evaluating patients (pts) with unexplained syncope. Current ILR-devices are equipped not only with patient – activated recording of electrocardiograms (ECG) but also with automatic activation capabilities. However, the clinical value of these features critically depends on the quality of ECG recognition. Method: An ILR was implanted in 78 conscutive pts (age: 19–85 years) with recurrent unexplained syncope. 64 pts received a device with automatic recording features (Reveal Plus 9526, Medtronic Inc.). Implant sites were chosen with respect to appropriate signal quality and stability. Auto activation parameters were set to the storage of up to 5 episodes (bradycardia <40/min; asystole >3 sec; tachycardia >165/min). Follow up was performed until arrhythmias were proven or excluded as cause of syncope or till battery depletion. A maximum of 5 episodes per patient was included into final analysis. Results: During a mean follow up of 7 months (1–18 months) 268 automatically recorded episodes were analysed. In 216/268 episodes (81%) activation was inappropriate due to oversensing or undersensing phenomena. In 43 episodes (16%) an intermittent total loss of contact was responsible for inappropriate activation. 2 automatic recordings (1%) occurred parallel to manual activation by the patient. Arrhythmia as cause of syncope was neither proven nor excluded with automatic activation alone. Conclusion: In clinical practice, automatic recording features are not useful due to significant sensing problems. Future devices should be equipped with more advanced sensing algorithms to support diagnosis even in pts who fail to activate the ILR manually.
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| 34-1 ANGIOTENSIN II RECEPTOR 1 BLOCKER IMPROVES NOT ONLY HYPERTENSION BUT ALSO VENTRICULAR ARRHYTHMOGENICITY Chikashi Suga, Kazuo Matsumoto, Ritsushi Kato, Toshimasa Tosaka, Atsushi Sakamoto, Madoka Nozawa, Yurika Hotta, Osami Komoto, Shigeyuki Nishimura, Hiroshi Suga*, Saitama Medical School, Saitama, Japan, *Suga Clinic, Saitama, Japan Purpose: Angiotensin II receptor 1 blocker (ARB) has been proven to improve cardiovascular mortality and morbidity. However, the influence of ARB on fatal arrhythmia remained unknown. The purpose of this study was to evaluate if ARB has any beneficial effect on ventricular arrhythmogenicity, and also if the effect is associated with the decrease of blood pressure. Methods: This study consists of 69 patients (30 males, mean age 63.8±10 years) with hypertension in whom valsartan was administrated from February 2001 to May 2002. We assessed mean blood pressure (MBP), RV5+SV1 on ECG, QT dispersion (QTD) and QTc dispersion (QTcD) before and 10 months later of introduction of valsartan administration. We also assessed correlation between the difference of QTD ("QTD) or QTcD ("QTcD) before and 10 month later of the valsartan administration and the difference of MBP ("MBP) or RV5+SV1 ("RV5+SV1) before and 10 month later of the valsartan administration. Results: When compared the values before and 10 months later of valsartan administration, MBP (119.9±12.1mmHg vs. 101.9±10.6mmHg, p<0.0001), QTD (60.3±16.8msec vs. 47±11.3msec, p<0.0001) and QTcD (62.6±17.1msec vs. 49.3±12.6msec, p<0.0001) significantly decreased but RV5+SV1 (2.62±1.09mV vs. 2.53±0.98mV, NS). There was no significant correlation between "QTD or "QTcD and "MBP or "RV5+SV1. Conclusion: QTD and QTcD decreased after valsartan administration. The decrease of QTD and QTcD did not correlate with the change of blood pressure or RV5+SV1. Thus, it is suggested that valsartan might have beneficial effect on ventricular arrhythmogenicity that could not explained by the improvement of hypertension or left ventricular hypertrophy.
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| 34-2 CLUSTERING OF VENTRICULAR ARRHYTHMIAS AS PREDICTOR OF DEATH IN DEFIBRILLATOR RECIPIENTS T. Stuber, C. Eigenman, E. Delacrétaz, Swiss Cardiovascular Center, Bern Background: Clustering of ventricular arrhythmias (VA) often occurs in patients with an implantable defibrillator (ICD), but its prognostic significance is not known. Methods: The incidence and the type of arrhythmias, and the incidence of appropriate defibrillator therapies were determined by reviewing stored electrograms. A VA cluster was defined as the occurrence of 3 or more adequate ICD interventions within 2 weeks. A VA storm was defined as the occurrence of 3 or more adequate ICD interventions within 24hrs. Results: 214 ICD recipients were followed during 3.3+/– 2.2 years (698 patient years). Ninety-eight VA clusters occurred in 51 patients, 75 VA storms in 44 patients. Mean age, left ventricular function and NYHA functional class were similar in patients with and without VA clusters. VA storm occurred in 39% (n=20) of patients who already had VA clusters and in 24% (n=51) of patients who didn't have clusters (p=.001). Kaplan Meier estimates of survival at 5 years in patients with and without clusters was 68% versus 92% (p=.001). Conclusion: clustering of VA episodes places the patient at risk to develop VA storm, and is an independent marker of increased risk of death.
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| 34-3 ARRHYTHMIA CLASSIFICATION VIA ATRIAL AND VENTRICULAR MORPHOLOGY Samir Saba, Qin Xi, Leonard Ganz, Kevin Heggs, Rick Clontz, Douglas Parkinson, Paul J. Wang, Zaffer A. Syed University of Pittsburgh, Pittsburgh, PA, St Jude Medical, Sylmar, CA, Stanford University, CA Purpose: We tested correlation waveform analysis (CWA) on atrial and ventricular electrograms (EGMs) to discriminate ventricular tachycardias(VT) from supraventricular tachycardias(SVT). Methods: Patients undergoing electrophysiologic testing were enrolled. EGMs during induced arrhythmias were compared to EGMs during sinus and pacing rhythm (as the templates) by assigning a CWA % match score. Results: Twenty-two patients (age=48+/–22years; 7 females; 16 SVT and 6 VT) were studied. Using a sinus template, atrial CWA%match of SVT and VT were 66%+/–20% and 93%+/–5% (P=0.0034), respectively. With a % match cutoff of 85%, sensitivity to diagnose VT was 100% and specificity to reject SVT was 80%. Furthermore, ventricular CWA % match of SVT and VT were 81%+/–12% and 72%+/–24% (P=0.13), respectively (cutoff=65%, sensitivity=50% and specificity=90%). Using an atrial pacing ventricular template, ventricular CWA % match of SVT and VT were 87%+/–9% and 76%+/–14% (P=0.028), respectively (cutoff=70%, sensitivity=50% and specificity=93%). Conclusion: Atrial CWA matching is superior to ventricular CWA matching in discriminating between SVT and VT. A combination of CWA matching in both chambers can potentially achieve better discrimination.
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| 34-4 MORPHOLOGY OF PREMATURE VENTRICULAR BEATS Kantoch MJ, Gandy JE To assess the morphology of benign premature ventricular beats (PVC's) in healthy young individuals, 111 ECG's and 287 ambulatory Holter monitors were reviewed in 128 patients with normal hearts (age 0.3–23 years, median 10.5 years, 72 males) and in 159 patients with heart disease (age 0.4–29 years, median 11 years, 92 males). In 151 Holter monitors, lead placement was modified in such a way that it allowed to assess the bundle branch block and the electrical axis of recorded PVC's. The correlation between the Holter monitor and the ECG in regards to the PVC bundle branch block morphology was 100%. In patients with normal hearts and normal ECG's, PVC's carried the LBBB morphology in 56% of cases, RBBB morphology in 30%, both in 9%, and the morphology could not be classified in 5%. The most common morphology was the LBBB with inferior electrical axis (39% by ECG and 38% by those Holter monitors which recorded electrical axis). The number of PVC's recorded by Holter ranged from 2 to 73146 (median 86) and there was no complex ventricular arrhythmia other than bigeminy. There was no particular circadian distribution of PVC's; 64 patients had more than 10 PVC's recorded by Holter and in 58% of those PVC's clustered during daytime hours. In 13 infants, LBBB PVC's were seen in 8 and LBBB with inferior electrical axis in 6. In patients with heart disease, complex PVC's were seen in 60% and bundle branch block morphology of both types was seen in 20%. The LBBB morphology was seen in 57% and RBBB in 22%. There was no correlation between the presumably affected ventricle and the morphology (origin) of PVC's. In conclusion, PVC's observed in young individuals with normal hearts do not differ from those recorded in patients with heart disease; there is no specific "benign" morphology of PVC's.
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| 34-5 T-WAVE AND QRS COMPLEX MORPHOLOGY AND VENTRICULAR TACHYARRHYTHMIAS Juha S. Perkiömäki, Elmo Niskasaari, Mari Karsikas, Tapio Seppänen, Heikki V. Huikuri, Division of Cardiology, Department of Internal Medicine and Department of Technology, University of Oulu, Oulu, Finland Purpose: To assess, if newer descriptors of T-wave and QRS complex morphology are specifically related to the risk of arrhythmic cardiac events. Methods: Of 66 patients with a history of myocardial infarction, 35 had no history of ventricular tachyarrhythmia (VTA) and no inducible VTA during programmed electrical stimulation (VTA -), and 31 had a history of sustained VTA and were inducible to sustained VTA (VTA+). Following T-wave and QRS complex descriptors were determined from the 12-lead ECG: the width (W), height (H) and dispersion (D) of the T-wave and QRS loops and the ratio of H and W (H/W), the cosine of the angle between the main vectors of T-wave loop and QRS loop (TCRT), and the sum of the maximum and minimum amplitudes of QRS complex (QRSsumA). Results: None of the studied T-wave loop or QRS loop descriptors descrimated the patients with and without vulnerability to VTA (p>0.5 for all). However, among the QRS sum amplitudes, QRSsumA in lead V5 differed most significantly between the groups (0.96 +\– 0.71 mV for the VTA - group versus 0.35 +\– 0.69 mV for the VTA+ group, p=0.001). QRSsumA remained as an independent descriminator between the groups after adjustment with clinical variables and ejection fraction; HR 3.41 for each 1 mV decrease in QRSsumA, 95% CIs: 1.13–10.28. Conclusion: None of the T-wave loop or QRS loop parameters descrimated the patients with and without vulnerability to VTA. However, a simple measure of the sum of the maximum and minimum amplitudes of QRS complex in lead V5 independently identified the patients with propensity to arrhythmias.
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| 34-6 PREDICTORS OF RESIDUAL RISK EVENT IN PATIENTS WITH ISOLATED SYNCOPE OR PRESYNCOPE AND A NEGATIVE ELECTROPHYSIOLOGIC STUDY A Da Costa, JL Gulian, C Roméyer-Bouchard, M Messier, N Zarqane-Sliman, B Samuel, A Kihel, K Isaaz -University of St Etienne, North Hospital, France This study targets predictors of cardiac rhythmic events in pts with an episode of syncope (S) or near S presenting with negative electrophysiologic study (EPS). A significant cardiac rhythmic event was defined as a combined end-point of symptomatic (1) AV block; (2) conduction abnormalities (Ab) requiring pacemaker therapy; (3) sustained ventricular arrhythmia; and (4) sudden death. Methods. All pts undergoing EPS after a first episode of S or pre-S between 01.97 and 12.01 were included. Results. Of the 329 pts (70±15 yrs;42.6% women)who underwent EPS, 305 (92.7%) had follow-up data. Pts were as following: history of myocardial infarction (MI) (12%)or AFib(10%), structural heart disease (17.4%), LVEF (61±11%) and ECG Ab (37%). These Ab included right (RBBB) or left (LBBB) bundle branch blocks, left anterior or posterior fascicular block (LAFB or LPFB), bifascicular block (RBBB + LAFB) and traces of MI. Follow-up was 31±20 months with 5% of pts recording arrhythmic events (15/305): AV block in 7 pts, sinus dysfunction in 4, sudden death in 3 and ventricular tachycardia in 1. Univariate analysis reveals structural heart disease, ECG Ab and LVEF associated with the risk of significant events. Multivariate analysis using a Cox model found that the only independent predictor was an ECG Ab. The long-term risk of event in the subset with ECG Ab is of 10.6% (12/113). If unexplained S recurrence was included, ECG Ab and LVEF were both determinants with a 13.3% (15/113) risk of events in the subset of pts presenting with ECG Ab and Cox model found ECG Ab as the only independent predictor. Conclusions. An ECG Ab is the only predictive variable associated with arrhythmic event in pts with a lone episode of S or near S and a negative EPS
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| 43-1 GENERATING AN ABLATION TIMING SIGNAL FROM THE ECG DURING ATRIAL FLUTTER (AFL) Alborz Hassankhani, Bobbi Hoppe, Gregory Feld, Valmik Bhargava, Sanjiv Narayan Univ California, San Diego, USA Background: Earliest atrial electrograms (EGMs) identify successful ablation sites in non-isthmus (NIDAFL) and isthmus- (IDAFL) dependent AFL, but may be difficult to locate. We hypothesized that EGM timing may be predicted from the ECG using spectral and correlation analysis. Methods and Results: In patients with IDAFL (n=19) and NIDAFL (n=15) we created an ECG-derived waveform by cross-correlating an F-wave template to successive ECG points. Waveform spectra showed peaks at 3.55±0.57 Hz, giving predicted AFL cycle lengths of 291.5±49.2 ms. This correlated closely with measured values in IDAFL (r=0.94; p<0.01) and NIDAFL (r=0.97; p<0.01). Careful template selection resulted in waveforms whose maxima (predicted EGM timing) in IDAFL fell within 10.8±7.72 ms of actual isthmus EGMs (Figure). In NIDAFL, predicted EGM timing fell within 17.1±12.1 ms of actual ablation site EGMs.
Conclusions: ECG spectral analysis may time the exit of atrial wavefronts from slow conduction zones in IDAFL and NIDAFL. Such "virtual electrograms" may help to locate potential ablation sites.
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| 43-2 CORRELATION BETWEEN AMPLITUDE OF SURFACE ECG FLUTTER WAVES AND RADIOFREQUENCY ENERGY AMOUNT REQUIRED TO BLOCK CAVOTRICUSPID ISTHMUS Rotter M; Hsu L-F; Jais P; Takahashi Y; Sanders P; Pasquié J-L; Sacher F; Hocini M; Clementy J; Haissaguerre M. Hôpital Cardiologique du Haut-Lévêque, 33604 Bordeaux Background: Ablation of typical atrial flutter can be achieved using limited radiofrequency energy (RF) application, although prolonged ablation may be required. This has been attributed to the cavotricuspid isthmus anatomy, in particular its thickness. We hypothesized that flutter wave (F-wave) amplitude on the ECG may be a marker of muscle mass and therefore would correlate with duration of RF energy required. Methods: We studied 50 consecutive patients in atrial flutter (42m;67±12y). Ablation of the isthmus was performed by creating a line of block between the inferior tricuspid annulus and the inferior caval vein using a standard non-irrigated 4 or 8mm tip catheter with the endpoint of bidirectional conduction block. F-wave amplitude was measured in the limb leads from peak to peak by blinded readers. Results: 13±9.6min of RF energy was delivered; fluoroscopy and procedure times were 12±7min and 42±19min respectively. F-wave mean values were in lead II: 0.29±0.09mV, aVF: 0.26±0.09mV, III: 0.28±0.09mV and aVL: 0.15±0.05mV. F-wave amplitude showed a linear correlation to RF energy applied to achieve conduction block (Lead II: r=0.401, p=0.005; aVF: r=0.416, p=0.003; III: r=0.498, p<0.001; aVL: r=0.478, p=0.001). An F-wave > 0.35mV in lead III predicted a RF delivery > 16min in 62% with a specifity of 91%. Conclusion: The F-wave amplitude showed a significant linear correlation with RF energy duration required to achieve bidirectional conduction block. F-wave amplitudes may be a surrogate marker of atrial muscle mass and isthmus thickness. These findings may influence the choice of catheter utilized for CTI ablation.
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| 43-3 INTERPRETATION OF THE MORPHOLOGIES OF ATRIAL FLUTTER WAVES AIDED BY THREE-DIMENSIONAL NONCONTACT MAPPING Jian Chen, Per Ivar Hoff, Ole Rossvoll, Knut Ståle Erga, Ole-Jørgen Ohm. Haukeland University Hospital, Bergen, Norway. Introduction: The mechanism of typical atrial flutter (AFL) has been well defined as a macroreentry circuit along the tricuspid annulus. It has been suggested that the polarity of a flutter wave is mainly determined by the left atrial activation. However, the morphologies of flutter waves on the surface electrocardiogram are not identical. We sought to interpret the morphologies of flutter waves aided by a three-dimensional noncontact mapping system. Methods and results: 33 patients (30 men, 3 women, mean 55±13 years) who had counterclockwise AFL were studied. A noncontact multielectrode array was employed to reconstruct electrograms in the right atrium. Conduction velocities in different zones along the tricuspid annulus were measured during AFL. The patients were divided into 2 groups based on the polarities of the flutter waves in the standard lead III (see tracings below). Type A: a negative flutter wave followed by a positive part and a plateau segment. Type B: a negative deflection not followed by a positive wave (or the amplitude < 0.05 mV) but only a plateau segment. The conduction velocities are faster in the upper and slower in the lateral right atrium in Type B compared with Type A. (The results are shown in the table. * P < 0.05)
Conclusions: The polarities of atrial flutter waves are partly determined by the right atrial activation, and it is related to the conduction velocities in the upper and the lateral right atrium.
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| 43-4 DURING INFERIOR VENA CAVA-TRICUSPID ANNULUS ITHMUS ABLATION THE PRESENCE OF CLOCKWISE CONDUCTION BLOCK INDICATES THE PRESENCE OF BIDIRECTIONAL BLOCK. X.Viñolas, E.Rodriguez, F.Freire, C. Grande, R.Oter, P.Torner, J.Cinca.Cardiology. H. de Sant Pau. Barcelona. spain Th endpoint of inferior vena cava-tricuspid annulus (IVC-TA) ablation is bidirectional conduction block. Evaluation of bidirectional block when using 3D electroanatomical mapping requires 2 maps. If the presence of unidirectional conduction block were premonitory of bidirectional block a single map would be required. Methods: 51 consecutive Patients (P) (86% males, 54y) with IVC-TA isthmus ablation. 4mm irrigated tip ablation catheters were used, during CS pacing. Pacing and recording across ablation line was performed using 2 deflectable multipolar catheters in CS ostium and in low right atrium (LRA) as close as possible to the ablation line. IVC-TA isthmus block was considered present when a line of double potentials (P1with isoelectric line in between was present, and when the second component (P2) of the double potentials was later than the LRA. After clockwise IVC-TA block was confirmed, counterclokwise conduction was evaluated. Results: ICT isthmus block was obtained in 50/51 patients. Low RA to CS (pre 77±16; post 129±25ms p<0,05) CS to Low RA (pre 80±15 post 115±2ms p<0,05) CS to P2=148±28ms; Low RA to P2= 145±30 ms; P1 to P2= 110±26 ms Conclusions: In our series of P the presence of clockwise conduction block during IVC-TA ablation indicated always the presence of bidirectional block. Thus, if this data are confirmed with larger series the evaluation of IVC-TA isthmus block when using for example 3D mapping systems could be simplified, requiring the creation of a single map during CS stimulation
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| 43-5 CHRONIC RESUMPTION OF ISTHMUS CONDUCTION AFTER ATRIAL FLUTTER ABLATION Bakthadze N, Ceriotti C, Zardini M Arrhythmia Unit, Humanitas Gavazzeni Hospital, Bergamo, Italy Inferior cavo-tricuspid isthmus (CTI) block is the success criterion of atrial flutter (AFl) ablation. However, recovery of CTI conduction is possibile and is associated with AFl recurrence during the follow-up. Aim of this study was to assess the long-term lesion stability in patients (pts) effectively treated for CTI-dependent AFl. Methods: from 01/00, 102 of 105 consecutive pts (mean age 61±9 years, 74% males) underwent on successful RF ablation of CTI in a single session, using a 4-mm (42%) or a 8-mm tip (58%) catheter. A control electrophysiologic study was performed at a median of 2 months (1–6) from the ablation, independently from the presence of recurrent symptoms or arrhythmias, and ablation was repeated if recovery of CTI conduction was evident, as demonstrated by conventional pacing/mapping maneuvers. Results: at the time of the control study, 6/102 pts (6%) have had recurrent symptoms or documented typical AFl. A recovery of CTI conduction was demonstrated in 33 pts (Group A - 32%), including the 6 symptomatic pts and 27 asymptomatic pts. Persistent CTI block was present in 69 pts (Group B - 68%). Among the procedural variables, a significative difference between the two groups was observed for the mean RF time (973±322 vs 494±223 sec, p<0.0001) and percentage of large-tip catheter usage (24% vs 74%, p<0.001). All pts with recovery of CTI conduction were effectively reablated. During a follow-up of 19±11 months, typical common AFI recurrences occurred in 1 patient (1%). Conclusions: chronic recovery of CTI conduction after a successful ablation may occur in over 30% of cases, and is dependent on the ablation technique used, probably as a consequence of deeper or wider lesions obtainable with large-tip catheters.
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| 43-6 WAVEFRONTS SHOW GREATER VARIABILITY IN NON-ISTHMUS THAN ISTHMUS-DEPENDENT ATRIAL FLUTTER Sanjiv M. Narayan, MD, Alborz Hassankhani, MD, Bobbi Hoppe, MD, Gregory Feld, MD and Valmik Bhargava, PhD. University of California and VA Medical Centers, San Diego, USA Background: We hypothesized that unique anatomic and functional characteristics of isthmus.dependent (IDAFL) atrial flutter would lead to greater stability in its circuit compared to non.isthmus dependent atrial flutter (NIDAFL). To test this hypothesis, we developed algorithms to detect subtle temporal and spatial ECG F.wave variability in patients with NIDAFL versus IDAFL, and validated these findings during mapping at electrophysiologic study (EPS). Methods and Results: We studied 23 patients with NIDAFL and 39 with IDAFL. The dominant ECG F-wave spectral peak was of lower magnitude in NIDAFL than IDAFL, suggesting variable atrial timing (>6 dB in 5/23 cases vs 39/39 cases; p<0.01). Spatially, ECG atrial vectors were consistent between F-waves in all cases of IDAFL (figure: consistent loops in the XZ plane), but varied significantly in 22/23 cases of NIDAFL (variable loops; p<0.01). Mapping at EPS showed greater standard deviation of atrial cycle length in NIDAFL than IDAFL at lateral (7.3+3.0 vs 4.4+2.3 ms; p<0.01) and septal (7.4+6.4 vs 4.3+2.7 ms; p=0.03) right atrium, and proximal (6.9+6.1 vs 3.2+1.8 ms; p=0.02) and distal (7.4+5.8 vs 3.8+1.6 ms; p<0.01) coronary sinus. Spatial variability (in bi-atrial activation sequence) was also greater in NIDAFL than IDAFL (p=0.02). Conclusions: NIDAFL shows greater cycle-to-cycle variation in wavefront activation time and sequence than IDAFL. These differences may be detected from the ECG using temporal and spatial phase analyses. These results have implications for guiding ablation and support the concept that IDAFL and NIDAFL lie along a spectrum of intracardiac organization.
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| 44-1 TESTING TARGET NAVIGATION IN MAGNETIC CATHETER MANEUVERING SYSTEM FOR PULMONARY VEIN ISOLATION AND LEFT ATRIAL LINEAR LESIONS IN A CANINE MODEL Hiroshi Nakagawa, MD, PhD, Warren M Jackman, Cardiac Arrhythmia Research Institute, University of Oklahoma, Oklahoma City, OK, USA A magnetic catheter maneuvering system (MMS, Niobe, Stereotaxis-Siemens) has been developed to automate the motion of a mapping/ablation catheter. The MMS contains single plane X-ray, 2 computer controlled magnets which generate a magnetic field in any direction to direct a ablation catheter (with small magnet in the tip), and a device to advance/withdraw the catheter. The purpose was to test in dogs a target navigation (TN) program in MMS by directing an ablation catheter to isolate the right (RS) and left superior pulmonary vein (LSPV) and create linear lesions between PVs. Methods: 5 dogs (36–40 kg) were studied. Using transeptal approach, a Lasso catheter and an 8F magnetic ablation catheter (2.5mm saline irrigated electrode) was inserted into LA. For TN, the fluoroscopic location of each Lasso electrode in PV was registered in the navigation computer. A line between RSPV and LSPV was registered using the RAO and LAO location of electrodes along a liner catheter (3/5 dogs) or integration of a spiral CT image of the LA and PVs (1/5 dogs) Results: TN computer directed the ablation catheter precisely to approximately 50% of the registered (target) sites. Alteration of the magnetic field from the workstation was required to reach the remaining target sites. RSPV and LSPV were isolated in all 4 dogs using 6–18 (median 10.5) RFs and 3–11 (median 5) RFs (<35 watts). Linear lesions between PVs were created in all 4 dogs using 7–11 (median 9) RFs. Histology showed continuous and transmural lesions in 4/4 dogs. Conclusions: MMS with an irrigated ablation electrode allows consistent PV isolation and creation of linear LA lesions in dogs.
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| 44-2 ISOLATION OF PULMONARY VEINS GUIDED BY BASKET CATHETER MAPPING TO CURE ATRIAL FIBRILLATION Scaglione M, Caponi D, DiDonna P, Bocchiardo M, Sartori P, Defilippi G, Gaita F. Electrophysiology Laboratory. Department of Cardiology, Hospital of Asti, Italy. Aim: To verify the feasibility, safety and efficacy of isolation of pulmonary veins (PV)guided by basket catheter (BC) mapping to cure atrial fibrillation (AF). Methods: 145 patients (pts), 81 males, 64 female, (mean age 50±16 yrs) with idiopathic paroxysmal and persistent AF refractory to antiarrhythmics drugs, underwent electrical isolation of all PV. PV angiography was performed pre and after the ablation. The target of ablation were the breakthrough of the vein mapping its ostium with a BC with 64 electrodes. The BC conformed its shape to the vein allowing a reliable target for ostial ablation and a detailed electrical multipolar mapping. RF was delivered point by point using a 7 F open loop cooled catheter in power control mode (up to 40 Ws, 45° cut off, 30 ml/min flow). The end point was the elimination of all ostial PV electrograms on the BC. Results: Complete PV isolation was obtained in all pts. The median number of RF pulses was 29. No significant PV stenosis were detected, we had one pericardial effusion and one late femoral haematoma. During a mean follow up of 11 +/– 10.9 months, 107/145 pts (74%) were free from AF in drug therapy (55% without drug). Analysing the two subgroup of pts the success rate was respectively 80% in paroxysmal AF and 62% in persistent AF (with drugs). Conclusion: RF isolation of pulmonary veins guided by BC mapping is feasible and safe with a good efficacy. The use of the BC may minimize the risk of PV stenosis both reducing the number of RF pulses and also avoiding the inadvertent ablation inside the vein.
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| 44-3 PULMONARY VEIN ISOLATION BY USING LOCALISA 3D NAVIGATION SYSTEM TO TREAT DRUG REFRACTORY ATRIAL FIBRILLATION. M. Rillo, G. Vetrone, S. De Vivo, A. Calcopietro, G. Cellamare, E. Manente, F. De Rosa, A. Ponzi*, M. Traverso*, G. Chiarandà, B. Villari - Sacro Cuore di Gesù Hospital - Fatebenefratelli - Benevento - Italy; *Medtronic Italy. This report presents our results of RF pulmonary vein (PV) isolation (I) by using LocaLisa 3D navigation system (LL). Method: 75 patients (pts) suffering from Atrial Fibrillation (AF) in spite of 2±1 antiarrhythmic drugs (AAD) underwent PVI; 15 pts had structural heart disease (SHD). Ablation (Abl) was performed along the PV ostia (os) after angiography. The PVos and the Abl sites were represented with LL. PVI was demonstrated by Haissaguerre's electrophysiological criteria. Results: three months after 1st Abl 33 pts (44%) were free of AF (no-AF) without AAD and 15 pts (16%) with AAD. All pts with AF (n=27, 40%; 12/27 with SHD) and no-AF pts with AAD underwent a 2nd Abl. PV-atrial connection was demonstrated at 128/158 PVos treated (81%) and a new Abl was performed. Three months later 8/42 pts (19%) treated with the 2nd Abl were no-AF without AAD and 7/42 (17%) with AAD; all SHD pts were still in AF. The remaining 12 non SHD pts with AF underwent a 3rd Abl which demonstrated no PVos disconnection. At 1 year follow up, 40pts were no-AF without AAD (53%) and 9 pts with AAD (12%); AF recurred in 12/15 SHD pts (80% of all SHD pts) and in 14/60 non SHD (23%). The overall successful Abl rate was 67% in non SHD pts without AAD (77% with AAD). Procedural and fluoroscopy time in minutes were respectively 150±10 and 35±15 for the 1th Abl, 68±19 and 20±5 for the 2nd, 45±5 and 15±2 for the 3rd Abl. Conclusion: LL is useful in performing RF PVI. PVI proved to be effective in AF treatment especially in non SHD pts. LL is also useful to reduce fluoroscopy and procedural time
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| 44-4 COMPARISON OF NAVEX VERSUS CARTO GUIDANCE OF WIDE AREA CIRCUMFERENTIAL LEFT ATRIAL ABLATION OF PULMONARY VEINS T. Jared Bunch, Douglas L. Packer, Mayo Clinic, Rochester Objective: We compared electro-anatomic (Carto, Co) and impedance ranging (Navex, Nx) for wide area circumferential ablation (WACA) of the LA outside of the pulmonary veins (PVs). Methods: Simultaneous Co- and Nx-based LA and PV geometric rendering, activation mapping, and ablation sequence cataloguing were undertaken in 5 patients with drug refractory AF. Results: LA geometry was completed in 9±0.1 (Co) versus 11±0.9 mins (Nx). PVs, including the veno-atrial junction, was completed in 12±0.6 (Co) and 9±0.2 mins (Nx). LA activation mapping was possible with Co. Nx allowed side-by-side visualization of geometry with imported CT images. Foreshortening of the posterior wall (right-left PVs) was more common with Nx(Co: 29±4 mm, Nx: 15±14 mm, p=0.06). Lesion locations of 46±19 energy deliveries were made on respective geometries using 695±89 (Co, 3mm) and 371±183 (Nx, 4 mm) markers (p=0.008). Interactions between Nx and the Stockart generator required impedance compensation to prevent catalogue distortions. The superior-inferior distance (mm) of the WACA ring around paired PVs was comparable [left PVs (Co: 49±7, Nx: 41±21, p=0.44), right PVs (Co: 43±10, Nx: 47±13, p=0.60)], and as well as the side-side width (mm) [left (Co: 27±12, Nx: 30±6, p=0.63), right (Co: 29±10, Nx: 26±8, p=0.62)]. The ablative line length (mm) across the lateral LA isthmus was 29±8 (Co) vs 38±26 (Nx), p=0.48. WACA ring gaps were more apparent on Nx(14.3±12.5 mm/study) than Co(1 gap of 2 mm), p=0.04. Conclusion: WACA around PVs can be guided by both systems. Each provide robust geometric renderings of PVs and LA, and catalogue ablation sites to comparable dimensions, although impedance variability creates distortions with Nx, requiring compensation.
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| 44-5 A NOVEL NON_FLUOROSCOPIC NAVIGATION SYSTEMTOGUI ISOLATION C. TONDO, MD, PhD; M.MANTICA, MD; A.LUCCHINA, RN, F.NIGRO, RN; M. WILD, RN; L.COLLARI Achievement of pulmonary vein (PV) isolation is critical to control atrial fibri approach requiring several radiofrequency (RF) current applications and long X_ role of a novel non_fluoroscopic navigation system (EnSite NavX, ESI, Inc) toguidec conventional fluoroscopic approach. Methods. In 10 patients (pts) (Group A) (system yielded the virtual 3_D reconstruction of PV ostia and the surrounding Based on the 3_D map, RF current was delivered at the atrial site of PV ostia unti (Group B) (10 males, mean age 55±8 years), PV isolation was performed under f in both groups. Mean X_ ray time was 22±8 min in Group A and 64±10 min inGr circumference thus, guiding PV isolation with a mean number of 5±1 RF applic B (p<0.05). The procedure mean duration time was 220±15 min in Group A and A pts, the left isthmus line was created based only on the EnSite NavX system g guide to isolate PV, promoting a 3_D reconstruction of PV ostium and the su exposure and the RF applications. Furthermore, preliminary findings indicate a p left linear lesions.
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| 44-6 CIRCUMFERENTIAL ABLATION OF PULMONARY VEIN FOR ATRIAL FIBRILLATION USING 3B-ELECTROANATOMIC APPROACH Wnuk-Wojnar A.M., CzerwiDski C., Wozniak-Skowerska I., Nowak S., Hoffmann A., Rybicka-Musialik A., Drzewiecka-Gerber A., Krauze J., SzydBo K., Trusz-Gluza M. 1st Dept. Cardiology, Silesian Medical Academy, Katowice, Poland Aim of the study was to evaluate the safety and efficacy of circumferential pulmonary vein (PV)ablation for atrial fibrillation (AF). To obtain electrical PV isolation we used electroanatomic approach with 3D guidance by Carto system. A total of 98 pts (56 M, median age 46 years)were referred for RF ablation because of recurrent paroxysmal (76%)or permanent AF: 57% of then with hypertension, 22% with IHD.After completion of electroanatomic map (EAM) of left atrium (both anatomic and voltage map)and PVs identification circumferential RF lesions were created with the aim of disconnecting these veins from left atrium defined by a bipolar amplitude <0,1 mV insidethe encircled lesion. In 32 pts procedure was performed during AF. SR was restored during RF application in 11 pts, in further 21 by DC cardioversion. Voltage remap after ablation revealed electrical silence not only around PVs ostia, but also at posterior aspect of LA.In 3 pts pericardial effusion, in 1 pt retroperitoneal effusion due to heparin induced thrombocytopenia (HIT) and in further 1 pt hemoptoe due to segmental atelectasis and left superior pulmonary vein thrombosis were observed. During 3–18 months follow-up 6% of pts have still permanent AF. Single short lasting episodes of AF were observed in 57% of pts 1 month after ablation and only in 38% after 3 months. 6 months after ablation 76% of pts are free of symptomatic arrhythmia. In 57% of asymptomatic pts no AF was registered during 7days holter monitoring. In conclusion, circumferential pulmonary vein ablation is safe and successful method to prevent AF.
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| 49-1 A NEW LEFT VENTRICULAR LEAD IMPLANTABLE "OVER THE WIRE" OR STYLET DRIVEN: FIRST CLINICAL EXPERIENCE G. Prenner1, K. Tscheliessnigg1, M. Külschbach2, V. Paul3, C.C. de Cock4, H. Schwacke5, P. Diotallevi6, O. Bosse7, H- Flathmann8, on behalf of the OVID study investigators. 1University Hospital Graz, Austria; 2Bergisch-Gladbach, Germany; 3Chertsey, UK; 4Amsterdam, NL; 5Hamburg, Germany, 6Alessandria, Italy, 7Traunstein, Germany, 8Biotronik Erlangen, Germany. A key challenge in cardiac resynchronization therapy (CRT) is the implantation of the left ventricular (LV) lead. Although LV leads are meanwhile mainly inserted "over the wire" (OTW), the stylet driven (SD) approach may be a helpful alternative. A new polyurethane-coated, unipolar LV lead, Corox OTW/Steroid (Biotronik, Germany), can be placed either by a stylet or a guide wire, which is insertable from both ends into the lead body. The multicenter OVID study evaluates clinical performance of Corox OTW/Steroid. Methods: Primary endpoint is the lead implant success rate after the coronary sinus was found. Secondary endpoints include complication rate, acute and chronic lead parameters, skin-to-skin and LV lead placement duration, X-ray time, and lead handling characteristics ratings. Results: To date 15 heart failure patients (70 ± 9 years, 11 males, NYHA class III-IV, QRS duration 154 ± 22 ms) with indication for CRT are enrolled. In all Corox OTW/Steroid implantation attempts both OTW and SD techniques were used in changing orders. The SD approach was finally successful in one and the OTW approach in 11 cases. In one patient coronary sinus could not be found and in 2 patients neither Corox OTW/Steroid nor an alternative LV OTW lead could be placed in a stable position. Skin-to-skin duration for successful implantations was 121 ± 56 min, duration of LV lead placement was 36 ± 30 min, and X-ray time 32 ± 23 min. Mean pacing threshold at implant was 1.0 ± 1,0 V (pulse width 0.5 ms), R-wave amplitude 18 ± 8 mV, and pacing impedance 924 ± 425 Ohms. Conclusions: OVID data suggest that the use of Corox OTW/Steroid lead is safe and effective. The possibility to switch between OTW and SD techniques during implantation offers improved flexibility to the physician.
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| 49-2 COMPARISON OF STYLET VS. STEERABLE CATHETER FOR LEAD IMPLANTATION AT CONVENTIONAL AND ALTERNATE SITES Dr. Charles Byrd, Broward General Medical Center, Ft. Lauderdale, FL Purpose: A new steerable catheter delivery system (SCDS) was developed to replace the stylet during lead implantation. The goal is more efficient implants in conventional and alternate sites in the right atrium (RA) and right ventricle (RV). The trend to alternate site pacing is expected to grow to meet the demands for more physiologic pacing (RV apical lead placement has been shown to contribute to heart failure, atrial fibrillation, and mitral valve regurgitation). In addition, SCDS is needed to implant newer leads which have no stylet lumen. Methods: The 5076 lead was placed in specific locations in RA and RV using a stylet and a 10600 SCDS. An optimal implant site was selected using electrogram analysis, and the time-to-implant recorded. Summary of Results: The data below shows the atrial implant times were faster with the SCDS. This time to implant difference was not reflected in the ventricle, probably because more specific sites were explored with the SCDS. In general, the stylet was inefficient and less precise in comparison to the steerable catheter.
Conclusion: The SCDS allows for optimal lead implantation to both conventional and alternate sites in the RA and RV in a rapid, repeatable fashion. These results encourage more widespread physiologic pacing; which can be facilitated by catheter delivered leads.
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| 49-3 SAFETY AND HANDLING OF A NOVEL CATHETER DELIVERED PACING LEAD A.S. Manolis, C. Khazen, J. Villacastin, R. van Mechelen, B. Dokumaci, B. Hansky, E. Sousani, L. Kretzers, M. Gammage. Patras University Hospital, Patras, Greece, AKH Wien, Vienna, Austria, Clínico San Carlos, Madrid, Spain, St. Franciscus Gasthuis, Rotterdam, Netherlands, Eskisehir SSK Hospital, Eskisehir, Turkey, Herz- und Diabetes Zentrum Nordrhein Westfalen, Bad Oeynhausen, Germany, Medtronic, Athens, Greece, Medtronic, Maastricht, Netherlands, University Hospital, Birmingham, UK Recent data suggest that selective site pacing may be advantageous. The Medtronic SelectSecure is a 4.1 Fr. lead, which is designed for precise placement using the deflectable SelectSite catheter. In a prospective randomized study, this system was evaluated in a standard DDD(R) pacemaker population. 151 pts were implanted with 147 atrial and 142 ventricular SelectSecure leads: Coronary Sinus Ostium 73, Inter-Atrial Septum 74, High Anterior RVOT 73, and Low Septal RVOT 69. Lead handling met the expectations in 92% for all 4 sites, while catheter handling was satisfactory for all sites but Inter-Atrial Septum. According to investigators, leads were placed at the specified location in 78% of all cases. 14 atrial lead related events occurred in 12 pts (5 without invasive intervention), and 18 ventricular lead related events in 16 pts (7 without invasive intervention). Of those events, 6 atrial and 3 ventricular lead dislodgements required replacement, and 3 cardiac perforations required invasive intervention (1 sternotomy and 2 pericardiocentesis). 18 occurrences of catheter kinking were reported in 15 pts. Selective site pacing was effective with successful lead placement at all pre-specified sites in the majority of the pts, with satisfactory lead and catheter handling. Technical improvements of the guiding catheter will further facilitate selective site pacing.
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| 49-4 ACUTE EVALUATION OF A NEW VENTRICULAR PACING LEAD González Camino, Félix MD; Martín, María MD. University Hospital Central de Asturias, Spain. Introduction. The aim was to perform an acute evaluation of a new pacing lead placed in the ventricle. We have collected data on electrical performance, energy consumption and AutoCaptureTM (AC) compatibility. Method. The IsoflexTM S model 1646T (St. Jude Medical) is a straight, bipolar, silicone insulated lead. From December 02 to July 03, 37 leads were implanted in 37 patients (30M; age 74±10 years). Pacing indication was AVB (20), SSS (11), AF (4) and CSS (2). Once the optimal position was confirmed by X-ray and PSA measurements, the AffinityTM pacemaker (St. Jude Medical) with AC algorithm was implanted. A follow-up procedure was performed and, if appropriate, AC was enabled. Follow-ups were performed at 48 hours, day 10th, one month and 4 months. AC threshold was measured at 0,3 and 0,4 ms pulse width. The value which resulted in the lowest pulse charge, as calculated by µC=mA x ms, was then programmed. Results.See table below. AutoCapture could be enabled in all patients. Patients with AV conduction showed good R-wave sensing.
Conclusions. 1 This new lead showed good electrical performance al implant, as well as over time. 2. Low pulse charge. 3. Due to excellent Polarization and Evoked Response values, AutoCapture was programmed in all patients at implant.
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| 49-5 2 YEARS PERFORMANCE OF A PRE-CURVED LEAD FOR LEFT-VENTRICULAR PACING A Schuchert, V Paul1, K-H Seidl2, D Pfeiffer3, G Oltmanns4, W Daenschel5, M Aydin, A Polauck6, T Meinertz, University-Hospital Eppendorf, Hamburg, 1Harefield Hospital, UK, 2Hospital Ludwigshafen, 3University-Hospital Leipzig, 4DRK Hospital Soemmerda, 5Heart Center Chemnitz, 6St. Jude Medical, Eschborn, Germany Background: Technical goals for left ventricular (LV) leads are appropriate and stable lead positions with low pacing thresholds (PT), no extra-cardiac stimulation and few dislodgment. Aim of the present study was to evaluate the 2-years performance of a pre-curved LV lead. Methods: 102 heart failure patients(Pat) with bundle branch block were selected to receive sheath-assisted the unipolar pacing lead Aescula LV 1055K (SJM, Sylmar, CA). At each follow-up (FU), the electrical parameters and adverse events related to the pacing system were recorded and separately analyzed for Pat with left(LVP) and bi-ventricular pacing (BVP). Results: CS could be accessed in 98 and the lead was permanently implanted in 96 (94%) Pat. Skin-to skin procedure time was 98±28 minutes. During FU 3 Pat were re-operated due to phrenic nerve stimulation in 2 and hematoma in 1 Pat. PT was at implant 1.4 ± 0.9 V for LVP (n= 8) and 1.7 ± 0.5 V for BVP(n = 88). After an intermittent increase PT remained stable between 1.6 and 1.9 V for LVP and BVP. Device-based measured pacing impedance was significantly higher for LVP compared to BVP at implant (698 ± 296 ohms versus 380 ± 67 ohms; p < 0.05) and during FU. Sensing threshold at implantation was 14.3 ± 5.9 mV for LVP and 8.9 ± 3.2 V for BVP. After 24 months sensing threshold was 13.8 ± 7 mV for LVP and 12.8 ± 4.8 mV for BVP. Conclusions: The implantation of the pre-curved pacing lead was safe and success was 94%. Long-term performance was excellent with stable electrical lead parameters and few adverse events.
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| 49-6 FIRST CLINICAL EXPERIENCE WITH THE WORLDWIDE THINNEST (7.6 F) TRANSVENOUS DUAL COIL DEFIBRILLATION ELECTRODE R Grove, W Kranig, F Ritterfor European Riata Study Group, Heart Center Osnabrück/Bad Rothenfelde, Schüchtermann Klinik, Germany Introduction: The RIATA 1580/1581 (St. Jude Medical) screw in defibrillation electrode provides a mapping opportunity of intracardiac signals (R wave). Thus before definitely fixing the lead the best sensing position can be found. Methods: Included were 52 patients (pt) with standard implantable cardioverter/defibrillator (ICD) indication in whom the RIATA electrode was used. During the implantation procedure sensing of the R wave was measured with and without screwing the lead in, whereas stimulation threshold and impedance were obtained after active fixation. Follow up was documented for a 6 months period. Results: In 32/52 (64%) of pt the first mapping position showed acceptable results which were comparable after active lead fixation. 20/52 of pt needed repositioning of the electrode. In the definite lead position R waves were 10.5 +/– 2.6 mV (mapping position) and 9.9 +/– 2.4 mV (active fixation) respectively. During follow up R wave amplitude was 9.6 +/– 2.8 mV (discharge, n=52), 10.6 +/– 2.0 mV (1 month, n=46), 10.8 +/– 2.3 mV (3 months, n= 46) and 10.8 +/– 2.3 mV (6 months, n= 23). Stimulation thresholds (@ 0.5 msec)were 0.5 +/– 0.2 V at implant, 0.8 +/– 1.0 (discharge), 0.8 +/– 0.6 V (1 month), 0.7 +/– 0.6 V (3 months) and at the end of follow up 0.7 +/– 0,4 V (6 months). Lead impedances showed values of 473 +/– 131 Ohm (intraopeartively), 370 +/– 83 Ohm at discharge, and 373 +/– 81 Ohm (1 month), 380 +/– 75 Ohm (3 months), 365 +/– 67 Ohm (6 months) in follow up. No electrode dislocations or other lead related complications were observed. Conclusion: The St. Jude Medical RIATA high voltage electrode shows good and stable stimulation and sensing results. The lead design allows mapping of the intracardiac signal due to a reliable correspondence of measured R wave with and without active fixation. Thus the best lead position can easily be found.
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| 54-1 How to assess the efficacy of ICD detection functions? Rémi Nitzsché, Christine Henry, Alain Ripart, PhD. ELA Medical, le Plessis-Robinson, France. Many clinical studies intent to evaluate the efficacy of detection algorithms since detection enhancements are available in ICDs. However, examining the methodology of these studies, one can see that published results are finally not comparable, and for several reasons: Study material. Bench studies report results of testing on induced arrhythmias, whereas clinical studies evaluates spontaneous events. Bench testing does not precisely account for ICD-system electronics, and libraries of induced arrhythmias do not allow the evaluation of arrhythmia onsets and duration. In addition, induced arrhythmias may be markedly different from daily-life events. ICD settings. Detection algorithms are not systematically applied in the same zones among ICD models. Detection parameters (minimum rates and duration) may vary widely and affect VT prevalence and the results of the study. Some studies apply nominal detection settings, while others allow the reprogramming of the device during follow-up. Memories. All ICDs have limited memories, and the specific types of data storage determine which arrhythmias are analyzed. Also, when slowing below the detection rate, single sustained episodes are often counted as multiple episodes. In most studies, a few patients contribute a large number of episodes. While, from a theoretical point of view, a per-episodes analysis may be more accurate, from a clinical point of view a per-patient analysis appears preferable. Statistical methods, such as the Generalized Estimating Equation should be used to eliminate the bias introduced by these patients. Assessment variables. Whether the VT detection specificity or positive predictive value (PPV) should be reported remains uncertain. Specificity analyzes the proportion of SVT/ST inappropriately treated by the device, whereas PPV measures the appropriateness of delivered therapies. Both are dependent of VT prevalence, while detection efficacy (ratio of all correct diagnosis to all documented events) seems to be stable whatever is the detection rate. This list may be not exhaustive. But it clearly shows that more uniformity in study design is desirable to compare data and to address the issue of the real efficacy of these functions in clinical routine.
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| 54-2 OBTAINING SURFACE ECG FROM DEVICE EGMS Steven M. Greenberg David H. Hoch Stuart O. Schecter Joseph H. Levine Background: It has been hypothesized that a comparable Lead I surface ECG signal displaying both P and R waves may be generated directly from an implantable cardioverter defibrillator (ICD) can and an additional high voltage electrode placed in the superior vena cava (SVC). This study evaluated whether the Can-SVC electrogram (EGM) configuration is similar to the Lead I surface ECG. Methods: This paired sample prospective study included a total of 24 pts (age 74±8 years, 71% male). All participants were implanted with a SJM ICD capable of customizing and recording EGMs with the Can-SVC configuration. Electronic signal data from the Can-SVC EGMs and surface ECGs were recorded and archived by the programmer at either implant or follow-up visit, and correlation analysis was performed. Results: A strong correlation was found in the QRS duration (Can-SVC: 129±39 msec vs ECG: 121±29 msec, p=NS, r=0.88) and PR interval (Can-SVC: 254±60 msec vs ECG: 232±54 msec, p=NS, r=0.94) between both electrogram types. The surface ECG had significantly lower amplitudes in both R waves (ECG: 0.95±0.58 mV vs Can-SVC: 1.70±1.13 mV, p=0.025, r=0.73) and P waves (ECG: 0.1±0.03 mV vs Can-SVC: 0.33±0.24 mV, p=0.001, r=0.60). Correlation waveform analysis revealed that the two electrogram configurations are strongly equivalent for all patients (r=0.71±0.10). Conclusion: The EGM obtained from the customized channel of a SJM ICD programmed to the Can-SVC sensing configuration serves as a strong proxy for the surface ECG. These results not only have implications for use as a "leadless" ECG, but possibly for enhanced discrimination of arrhythmias and as a substitute for an atrial lead.
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| 54-3 Properties of bidirectional AV nodal conduction in patients with dual chamber ICD: impact on prevalence and appropriate detection of tachycardia with 1:1 AV nodal conduction. Anton Hahnefeld, Tomas Matis, Tobias Eisele, Michael Fiek, Christopher Reithmann Inappropriate therapy of supraventricular tachyarrythmias (SVT) by ICD patients is still a common problem. Dual chamber ICD should result in a higher specificity for proper discrimination. However, especially the supraventricular or ventricular tachycardias (VT) with stable 1:1 AV nodal conduction are often a problem for the dual chamber algorithms. Limited data exist to define the scope of this problem in the ICD population.
In this study, the bidirectional AV nodal conduction capability and prevalence of VT and SVT with 1:1 AV nodal conduction was assessed in 79 patients with dual chamber ICD. 4 of 79 patients (5%) has a complete AV block and 46 of 79 patients (58%) a complete VA block. 16% of the patients maintained 1:1 conduction to cycle length (CL) Conclusion. Brisk VA conduction is uncommon in patients with dual chamber ICD, However, tachycardia with 1:1 conduction is not rare. The most of 1:1 tachycardia is SVT with inappropriate therapy.
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| 54-4 DEFIBRILLATION THRESHOLD TESTING IN PATIENTS WITH ICDS IS INFREQUENTLY PERFORMED FOLLOWING CLASS III ANTIARRHYTHMIC TREATMENT Saxonhouse SJ, McIntyre S, Aranda JM, Conti JB, Burkart TA, Curtis AB. University of Florida.
Background: Studies suggest that up 70% of patients with an implantable defibrillator (ICD) require concomitant antiarrhythmic drugs (AADs) to reduce sustained arrhythmic episodes and to minimize device discharges. AADs may increase defibrillation thresholds (DFTs) and potentially alter efficacy of ICD therapy. Thus, DFT testing is recommended after AAD initiation. The aim of this study was to determine if ICD patients are evaluated by DFT testing following AAD use. Methods: A retrospective cohort analysis was performed on the University of Florida heart failure (HF) database, which includes patients referred for heart transplant evaluation from 1999 to 2003 and followed for HF management. A quantitative analysis of DFT testing following institution of AADs in patients with ICDs was performed. Results: A review of a random cohort of 125 patients with an EF Conclusion: DFT testing is underutilized in patients with ICDs who are started on AADs. The mortality in these patients is high in short term follow-up. These results suggest that routine DFT testing is necessary to assure adequate ICD therapy.
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| 54-5 DEFIBRILLATION THRESHOLD DETERMINATION BASED ON THE UPPER LIMIT OF VULNERABILITY B. Lemke1, A. Lubinski2. J, Müller3, U. Kreutzer4, J. Gill5, H. Bushnaq6, W. Mäurer7, F. Schnöll8, A. Schuchert9, T. Lawo1. 1Kliniken Bergmannsheil, Bochum, Germany; 2Medical University, Gdansk, Poland; 3German Heart Center, Berlin, Germany; 4Cottbus, Germany; 5London, UK; 6Halle-Wittenberg, Germany; 7Bayrueth, Germany; 8Grossgmain, Austria; 9Hamburg-Eppendorf, Germany. The upper limit of vulnerability (ULV) is the shock energy at or above which ventricular fibrillation (VF) cannot be induced even if the shock is delivered during the vulnerable phase of the cardiac cycle. Previous studies have shown that the ULV is a reliable predictor of defibrillation energy. The aim of our study was to validate the TULIP test protocol for estimation of defibrillation threshold (DFT) during implantable cardioverter defibrillator (ICD) implantation, based on the relationship between ULV and DFT. Methods: The stimulus-peak-T interval was determined during ventricular pacing at 150 bpm. The TULIP test starts at 13J induction energy. If induced, VF should be terminated by an 18J biphasic shock. If VF was not induced, the shock energy should be reduced successively to 11, 9, 6J, etc., until VF induction, The corresponding energies for defibrillation should be 15, 13, 9J (biphasic). in case of successful termination, a confirmation shook at the same energy level is demanded. Results: 98 patients (age 62 ± 12 years, LVEF 39 ± 16%), scheduled to receive an ICD from Biotronik, Germany, were prospectively enrolled. The TULIP test was successful in 79 patients (81%) in whom the mean induction and conversion energies were 7.2 ± 4.2J and 11.1 ± 3.3J, respectively. In 13% of the patients the first shock and in 6% the confirmation shock failed to terminate VF. The 2.8 ± 2.7 min duration from the first induction attempt to effective induction represents a well acceptable time for intraoperative testing. Based on our data, the energy of the first ICD shock should be 15J, which is significantly below the 30J energy programmed by the widely used function test. By halving the shock energy, a 50% reduction in charging time is possible. Conclusion: The TULIP test is an effective procedure requiring induction of only 2 VF episodes to estimate and confirm DFT during ICD implantation.
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| 54-6 SELF-MANAGEMENT OF SYMPTOMATIC REFRACTORY ATRIAL FIBRILLATION BY DUAL DEFIBRILLATOR Ricci R, Pignalberi C, Russo M, Grovale N, Vimercati M, Grammatico A, Santini M. S.Filippo Neri Hospital, Rome, Italy Background: Dual Defibrillator allows patients (p) with symptomatic recurrent atrial fibrillation (AF) to be automatically shocked in atrium or to self-manage the shocks using a patient activator. Methods. 12 p (100% M, mean age 66±6) with SND and at least 3 episodes of AF during the last year were implanted with a dual defibrillator Medtronic 7250 and received an external remote-control device (Patient Activator Medtronic 9964) in order to shock themselves in case of AF. Patient activator can be also used by p to detect AF without treat it. 75% of p had been hospitalised during the last year and 58% had required electrical cardioversion. AF was persistent in 33% and paroxysmal in 67%. Mean NYHA was 1.2±0.4 and mean EF was 54±16%. All patients were followed for 1 year. Results: AF recurred in 11/12 p (92%). 5/12 p (42%) shocked themselves for a total of 33 times. Mean shock number per p was 6.6±6.3 (range 2–14). All the shocks were delivered at the maximum of energy (27J). 91% of shocks were successful. 12% of shocks were followed by early recurrence of AF within 24 hours. 6/12 (50%) p asked for physician assistance during shocking because of shock related fear and anxiety. There were no adverse events related to shock delivery. Symptom number and frequency improved at 1-year. As regard to quality of life, p improved in all items of SF-36 questionnaire mainly in role functioning (p<0.05). Conclusions: Self-management of AF episode is reliable and safe in p with SND and recurrent symptomatic AF implanted with dual defibrillator. This approach can reduce hospitalisations and improve quality of life. A psychological support may increase p compliance.
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| 56PW-1 DOES A 8mm TIP ELECTRODE PRODUCE A LARGER LESION S Fukuta, T Iwa, M Fukcuta, I Kato, Y Suzuki, Y Wakida, T Ito. Aichi Medical University, AICHI, JAPAN Recently, ablation catheters with 8mm tip electrodes (C8), instead of 4mm tip (C4), are widely used for pulmonary vein isolation. We studied whether lesion volume and depth could be increased by the use of C8 under various conditions. In total, 400 points in 24 swine hearts were ablated with a C4 and C8 under a controlled constant fluid flow rate (zero to 55 cm/s) in a special jet bath. A temperature control output (60C) with a maximum of 35 or 50W was used and the size of the damaged tissue was examined after the ablation. The results are as presented below. Conclusions; Compared with the C4; 1) the C8 increased the lesion volume and depth at a fluid flow rates < 20cm/s. 2) At a fluid flow rate >30cm/s, the C8 produced longer, but shallower, lesions with horizontal catheter contact and smaller lesions with perpendicular contact.
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| 56PW-2 IMPACT OF POWER LIMITATION DURING TEMPERATURE CONTROL CATHETER ABLATION S Fukuta, T Iwa, M Fukuta, I Kato, Y Suzuki, Y Wakida, T Ito. Aichi Medical University, AICHI, JAPAN A power limitation within 35W (PL35W) during temperature controlled radiofrequency ablation (TCRFA) has been widely used for pulmonary vein isolation. We studied whether the lesion volume and depth could be decreased by this method under various conditions in vitro. In a jet bath, 160 points on 12 swine hearts were ablated by TCRFA (60C) both with a PL35W and with no limitation of the power (50W). The orientation of the 4mm tip ablation catheter was kept perpendicular or horizontal, and the catheter and tissue were exposed to a constant external flow at a rate of 0, 20, 30 and 55 cm/s. The representative results are presented below. Conclusions: A PL35W during TCRFA is not always safer than having no power limitation, since it increases the lesion volume and depth in some conditions. Perpendicular contact
Horizontal contact
The figure represents, which conditions the damage decreased, increased or was equal when using a power limitation.
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| 56PW-3 INJECTATE FLOW-DEPENDENCE OF HEATED SALINE-ENHANCED, "VIRTUAL ELECTRODE" RADIOFREQUENCY ABLATION Gregory Keith Bruce, Douglas L. Packer Mayo Clinic, Rochester, MN PURPOSE: We sought to determine the influence of flow rate and saline temperature in a novel catheter that injects heated saline creating a "virtual electrode" on the generation of large lesions in the canine ventricle. METHODS: 4 dogs underwent 30 epicardial ventricular RF deliveries with "virtual electrode" augmented, heated saline tissue injections for 120 seconds at injectate flow rates of 5–10 ml/min, power 40–125 W, and saline temp of 50–70 °C. RESULTS: Lesions tended to be full thickness at all setting. Increasing the flow rate predicted increased lesion size more than increasing the saline temperature:
CONCLUSION: Flow rate of the injectate during RF ablation augmented by "virtual electrode", heated saline tissue injection is critically important to the overall generation of large lesions resulting in full thickness ventricular myocardial ablations. Direct injection of heated saline into tissue creates larger lesions than are possible with standard closed loop or irrigation tip catheters through the combined effect of augmented heat transfer and increased delivered power.
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| 56PW-4 OPEN IRRIGATED- VS. SOLID 8-MM-TIP CATHETERS FOR RADIOFREQUENCY ABLATION OF COMMON-TYPE ATRIAL FLUTTER: A PROSPECTIVE AND RANDOMIZED COMPARISON H.U. Klemm, R. Ventura, S. Willems, T. Rostock, B. Lutomsky, C. Weiss, C. Demir, T. Meinertz; Department of Cardiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany Background: Open irrigated-and solid 8mm-tip catheters demonstrated to be safe and effective for radiofrequency current (RFC) ablation of common-type atrial flutter (AFl). However, prospective and randomized studies are missing in this setting. Methods: 130 consecutive patients (pts, 61±11 years, 106 male) with AFI were randomized to undergo AFl catheter ablation using a solid 8mm-(group A, 65°, 75W, 60s) vs. an open irrigated-tip catheter (group B, 65°, 50W, 60s, 17ml/min flow). Endpoint was a bidirectional conduction isthmus block. In cases of more than one transient isthmus block the catheter was changed (cross-over) to that one used in the other group. Pts remained in the original group for further analysis. Results: A similar number of RFC pulses (11±6 vs. 10±7) and fluoroscopy time (25±17 vs. 21±10 min) where needed to reach the endpoint in 100% in both groups. Cross-over was performed in 8 pts of group A after 19±3 RFC applications. After an additional 5±2 RFC pulses using an irrigated-tip catheter the endpoint was achieved. In group B no cross-over was necessary (p=0,003). The procedure duration was 2,6±0,6 and 2,3±0,6h (p=0,002) in group A and B, respectively. Conclusion: Open irrigated-tip catheters show superior efficacy compared to solid-8mm-tip catheters. To economize procedure duration and catheter expenses, especially for difficult ablation procedures with recurrent transient blocks, using an irrigated tip catheter should be the primary approach.
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| 56PW-5 RADIOFREQUENCY CATHETER ABLATION OF TIPICAL ATRIAL FLUTTER USING A NON-FLUOROSCOPIC NAVIGATION SYSTEM P. Agricola, A. Catanoso, M. Cacucci, M. Nanetti, P. Romagnoli, A. Foffa, P. Valentini, P. Gazzaniga, A. Lodi Rizzini, D. Tovena, O. Durin, G. Inama. Department of Cardiology, Mayor Hospital of Crema - Italy. Radiofrequency (RF) catheter ablation is the treatment of choice for Tipical Atrial Flutter (TAF), but is frequently associated with high radiation exposure time. Aim of the study: was to evaluate the efficacy and safety of RF ablation using a new non-fluoroscopic navigation system (LocaLisa, Medtronic Inc) for accurate real time 3D localization of intracardiac electrodes. We also evaluated whether the use of this novel system significantly reduced the radiation exposure. Materials: the LocaLisa Medtronic Inc. is a system that allows the 3D rapresentation of the heart space, displays in real time the position of the electrode in a system of coordinates X-Y-Z. In addition LocaLisa offering in each moment of the procedure a precise repositioning on an anatomic electrophysiologic marker previously found. Methods: we study a total of 30 patients (pts) with TAF, divided in two groups. Group A (15 pts) performed RF ablation with LocaLisa and Group B (15 pts) performed RF ablation with conventional mapping. Results: in all pts was achived a line of isthmus block. All pts were discharged without AA therapy. We didn't find significant differences in the total procedure time in the 2 groups. The total RX time in group A was 10.2 min. compare with 20.5 of group B (pConclusion: the LocaLisa imaging system allows an accurate mapping durin RF ablation procedures and the creation of linear lesions in the isthmus, reducing the fluoroscopy exposure time.
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| 56PW-6 DISCRIMINATION BETWEEN COMPLETE VS INCOMPLETE BLOCK IN CAVO-TRICUSPID ISTHMUS? Pawel Derejko, MD; Massimo Tritto, MD; Franciszek Walczak, MD, PhD; Lukasz J. Szumowski, MD, PhD; Wojciech Krupa, MD, PhD; Dariusz Kozlowski, MD, PhD; Ewa Szufladowicz, MD, PhD; Piotr Urbanek, MD; Roman Kepski, PhD; Roberto De Ponti, MD; Grazyna Swiatecka, MD, PhD and Jorge A. Salerno, MD, PhD. Department of Rhythm Disturbances, Institute of Cardiology, Warsaw, Poland. Department of Cardiology, University of Insubria, Mater Domini Hospital, Castellanza, Italy. 2nd Department of Cardiology, Medical University of Gdansk, Poland. The aim of the study was to establish which variables are the most useful for differentiation between complete vs incomplete block in the cavo-tricuspid isthmus (CTI). Methods: 72 assessments were made: 57 after block, 15 during incomplete block. Mapping of the ablation line and differential pacing from LLRA and MRA with recording form proximal CS were done. The following parameters were measured: the difference between LLRA-CS and MRA-CS time intervals 9LLRA-MRAdiff); average (S-ATavr), minimum (S-ATmin) and maximum (S-ATmax) time intervals from stimulus to the terminal potential of double potentials (DP); the average (AT-AIavr), minimum (AT-AImin) and maximum (AT-AIavr) interval between initial and terminal components of DP. Using this variables discriminant function analysis was performed in the forward stepwise mode. Results: The only independent variable, which discriminated between complete vs incomplete block was S-ATmin (Wilks Lambda=0,76; p<0,000. Mean (±SD) S-ATmin intervals during complete and incomplete CTI block were 161,6±20,9 and 123,5±15,5 ms, respectively. 87,5% of cases (53,3% with gap; 96,5% with complete block) were correctly classified. Conclusion: S-ATmin obtained during line mapping is useful in discrimination between complete vs incomplete block in the CTI.
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| 56PW-7 ELECTROANATOMICAL MAPPING OF FOCAL ATRIAL TACHYCARDIA: THE EFFECT OF DIFFERENT ANNOTATION STRATEGIES FOR LOCAL ACTIVATION TIME DETERMINATION Ioan Liuba, MD, Anders Jönsson, MD, Kåge Säfström, MD, PhD, Håkan Walfridsson MD, PhD Background: The CARTO system is a widely used electroanatomical mapping system. However, at present there are no standard criteria for activation time determination with this technology. The aim of the present study was to compare the local activation time obtained with different annotation strategies during mapping of focal atrial tachycardias (FAT). Methods: Eleven consecutive patients with FAT and without underlying heart disease were investigated. During mapping, the activation time was measured at the bipolar electrogram's peak amplitude (Bi-peak). After ablation, signals were retrospectively analyzed and the activation time was successively defined as the earliest steepest negative deflection of the unipolar electrogram (Uni) and the earliest onset of the bipolar electrogram (Bi-on) respectively. Results: 827 electrograms were analyzed. The local activation time with both Bi-peak and Bi-on criteria was highly correlated with the local activation time defined by Uni (r=0.99, p<0.0001 and 0.97, p<0.0001 respectively). The diameter of the region of earliest activation (4±5 mm for Bi-peak, 2±2 mm for Bi-on and 2±5 mm for Uni respectively, p=NS) was similar in the 3 criteria. However, while the Bi-peak and Uni criteria generated similar activation times, the Bi-on measured significantly earlier activation times as compared to Bi-peak and Uni (11±2 ms earlier than Uni, p<0.0001 and 14±11 ealier than Bi-peak, p<0.0001). Conclusion: Activation time measured by Bi-on is significantly earlier than that generated by Uni. However no differences were noted between Bi-peak and Uni, fact indicating that Bi-peak reflects more accurately the local activation times in these patients as compared to Bi-on.
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| 56PW-8 A NEW CURATIVE TREATMENT FOR PAROXISMAL ATRIAL FIBRILLATION(PAF) USING THE FOURIER RIGHT-SHIFT TO GUIDE THE RF-ABLATION Pachon JC, Pachon EI, Pachon J, Pachon MZC, Lobo TJ, Albornoz RN, Sousa LCB, Jatene AD - Sao Paulo Heart Hospital, SP, Brazil Background: By studying the fast Fourier transform(FFT) of atrial potentials we have found 2 types of atrial myocardium: compact(CM) and fibrillary(FM). The former has normal-phased conduction, many cells connections, long refractoriness and Left-FFT-shift. The latter shows anisotropic-dephased conduction, fewer cells connections, short refractoriness and Right-FFT-shift. The CM is the normal. The FM may be congenital(vein insertion, IA septum, LA roof) or pathologic by losing cells connections that converts the CM into FM. We have found more PAF as the FM/CM ratio increases because the dephased FM favors reentry, reflection and refr. dispersion(AF-nests). Purpose: 1.To describe a new method for PAF RF-ablation targeting AF-nests; 2.The concept of FM; 3.The FM/PAF relation. Method: 22p(47.3±14yrs) having idiopathic drug-refractory PAF with normal LA. RF(30J/70°C) was applied (trans-septal->LA) in all sites outside pulmonary vein(PV), with Right-FFT-shift (FM potentials/AF nests) until left FFT-shifting. Results: The main FM places were: near PV(LS 21, LI 16, RS 17, RI 9), LA roof 22, Left IA septum 19, LA post wall 3, SVC 2 and RA 5. FM near PV were ablated resulting in 32 PV isolation. After 6.3±2months the p are cured except 2(9.1%) with recurrence being very well-controlled with low dose of previously ineffective drugs. There were no complications. Conclusions: 1.FM and AF-nests are new concepts and cause PAF; 2.They may be easily identified by Right-FFT-shift; 3.Elimination of many FA-nests with RF decreases the FM/CM ratio and cures the PAF; 4.PAF may be cured applying RF in several places outside the PV presenting FM potentials.
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| 56PW-9 ELECTRICAL AND ANATOMICAL EVALUATION OF THE LEFT SUPERIOR PULMONARY VEIN OSTIUM Reis-Santos K, Adragao P, Cavaco D, Ribeiras R, Morgado F, Aguiar C, Chotalal D, Bonhorst D, Seabra-Gomes R. Hospital Santa Cruz, Portugal Background: The relation between anatomical and electrical ostium of the pulmonary veins (PV) has yet to be established. RF energy applications distal to the anatomical ostium are risky since they may cause PV stenoses. Patients referred for atrial fibrillation (AF) ablation via PV isolation are routinely submitted to a transoesophageal echocardiographic study (TEE). Anatomical left superior (LS) PV ostium is systematically measurable. Electrical ostia of the PV are defined during electrophysiological study. We aimed to determine the difference between electrical and anatomical ostia of the LSPV. Methods: We studied 11 patients who underwent electroanatomical mapping and PV isolation guided by a circular catheter (Lasso). The anatomical ostium of the LSPV was defined by multiplane TEE as the largest diameter measured at the connection between the PV and the left atrium (LA). The electrical ostium of the LSPV was defined as the region where the electrical signals of the LA and the PV were contiguous during coronary sinus pacing. The vertical and horizontal diameters of the electrical ostium were measured using the CARTO system, and compared with the LSPV diameter measured by TEE. Results: The average horizontal diameter of the electrical ostium was 15.69±3.54mm, and the average vertical diameter was 18.02±3.68mm (p=ns). The anatomical diameter obtained by TEE was 12.64±2.02mm, and significantly different to both of the electrical diameters (p<0.05; paired t-test). Conclusion: The electrical ostium of the LSPV is larger than the anatomical ostium, that is, more atrial in location. These results suggest that as long as RF energy is applied on the electrical ostia the risk for PV stenosis is low.
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| 56PW-10 DEMONSTRATION THE ELECTRICAL RELATIONSHIP BETWEEN LIGAMENT OF MARSHALL AND LEFT ATRIUM IN CANINES Dong JZ, Liu XP, Long DY, Liu XQ, Ma CS. Department of Cardiology, Beijing Anzhen Hospital, Beijing, 100029, China Objective: To demonstrate the electrical relationship between ligament of Marshall(LOM) and left atrium in canines. Methods: Epicardial mapping of the LOM was carried out in 19 mongrel dogs using a decapoles comb-like mapping catheter. Chemical ablation was performed by injection of alcohol at the entrance of the LOM into the CS and the left atrium. The endpoint of the ablation was LOM isolation which defined as the disapperence of the LOM potentials. Results: The LOM potentials could be recorded in 89.5% (17/19) dogs. During sinus rhythm, each beat consists of two components with the first one stands for atrial electrogram and the second one represents LOM potential. The atrial activation delayed gradually from atrium to CS, whereas the LOM potential sequence presented 2 patterns: `LOM potentials advanced gradually with the earliest activation at the CS (13 dogs, Group A), and a the earliest activation of LOM registered both at the CSand at the middle segment of LOM (4 dogs, Group B). After ablation at the entrance of LOM to CS, the LOM potentials disappeared in Group A, whereas in Group B, the LOM potentials still existed eliminated until an extra ablation at the atrial posterior wall entrance along the middle segment of the LOM were performed. Conclusions: The conjection of the LOM with the left atrium was positioned at two sites :one was at the CS, anther was at the atrium. Key words: ligament of Marshall, epicardial mapping, alcohol, ablation
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| 56PW-11 IMPACT OF INTERVENTION IN LEFT ATRIAL ISTHMUS ON THE INDUCIBILITY OF ATRIAL FIBRILLATION IN CANINES AND ITS UNDERLYING MECHANISM Ma CS, Dong JZ, Liu XP, Long DY, Liu XQ. Department of Cardiology, Beijing Anzhen Hospital, Beijing, 100029, China Objective: To investigate the impact of intervention in left atrial isthmus (LAI) on the inducibility of atrial fibrillation(AF) in canines and its underlying mechanism. Methods: In 11 normal dogs, intervention in LAI was carried out through a linear incision from left inferior pulmonary vein to coronary sinus under general anesthesia. Before intervention, epicardial mapping of ligament of Marshall (LOM) with a 10 poles, 2 mm inter-electrode space and comb-like catheter were carried out first, and then, the conduction time of LAI was measured. AF was induced by S1S2 and S1S1 stimulations at different atrial site. AF was considered inducible only in two situations as follows: `AF could be reinduced with same stimulation protocol 3 times, and athe duration of AF more than 10 seconds. After intervention in LAI, above-mentioned electrophysiological studies were redone and the dogs were divided into Group A or Group B in terms of whether LOM potentials disappeared or not. Results: LOM potentials could be recorded in 100%(11/11) dogs before intervention in LAI. After intervention, LOM potentials disappeared in 6 dogs (Group A) and still exist in another 5 dogs (Group B). The inducible rate of AF before intervention was 100% in both Groups, but it was significantly higher in Group B (80%) than that in Group A(16.7%) after intervention (P<0.05). There wasn't significant difference in LAI conduction time before and after intervention in both Group A and Group B, respectivley. Conclusions: Intervention in LAI could reduce the inducibility of AF in normal canines, which is resulted from the concomitant electrical isolation of LOM,but not from conduction block of the LAI.
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| 56PW-12 RESULTS OF RADIOFREQUENCY ABLATION OF INFERIOR PARASEPTAL ACCESSORY PATHWAYS. Revishvili A.Sh., Rzaev F.G., Davtyan K.V., Kuptsov V.V Bakoulev Center for Cardiovascular Surgery, RAMS, Moscow, Russia. Objectives. This study was performed to assess the results of radiofrequency catheter ablation (RFA) of inferior paraseptal accessory pathways. Methods. We performed RFA in 72 WPW syndrome patients with inferior paraseptal accessory pathways (23.5% of all WPW syndrome patients) from January 2000 to October 2003. Of these 41 had manifesting WPW syndrome, 31 had concealed accessory pathways (14 of these were slow-conducting). Contrast fluoroscopy of coronary sinus was performed in 34 patients, in 16 of those posterior heart vein was visualized. 11 of them had aneurysm of posterior heart vein. As few as 15 patients (20.8%) had site of earliest activation located epicardially 0.2–2 cm inside coronary sinus, and effective ablations were performed at these sites. In 7 cases we ablated slow conducting concealed accessory pathways. We used cool-tip catheter ablation in 25 patients(34.7%). In 8 cases required retrograde transarterial approach and successful ablation was perfofmed in the left paraseptal region. Success rate in this series was 95%. In two unsuccessful cases we proceeded to perform surgery using Sealy technique (with cardiopulmonary bypass in minimally invasive approaches). Conclusion. Coronary sinus contrast fluoroscopy should be done in paraseptal accessory pathways ablation and this considerably enhances accessory pathways localization. When there are coronary sinus posterior heart vein aneurisms or the accessory pathways are frequently located near them. In no less than 40% cases the cool-tip ablation catheter use is required for paraseptal accessory pathways ablation. Unsuccessful RFAs are due to pyramidal localization of accessory pathways.
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| 56PW-13 PLASMA BRAIN NATRIURETIC PEPTIDE AS A PREDICTOR FOR SUCCESSFUL CATHETER ABLATION IN PATIENTS WITH SYMPTOMATIC IDIOPATHIC VENTRICULAR TACHYCARDIA Goro Shinbo,Hiroshi Tada,Shigeto Naito,Shigeru Oshima,Koichi Taniguchi,Gunma Prefectural Cardiovascular Center The purpose of this study was to clarify the relationship between Frequent premature ventricular contractions(PVC)and cardiac natriuretic peptides. The subjects of this study were 78 patients(pts)with symptomatic, non-sustained idiopathic ventricular tachycardia (NSVT)or PVC originating from the outflow tract (I-VT;NSVT-30,PVC-48). Measurements of the plasma atrial natriuretic peptide(ANP)and brain natriuretic peptide(BNP)concentrations and echocardiographic parameters were performed in all pts. In 66 pts, they were also performed after catheter ablation (CA). 1) BNP and ANP levels exceeded normal range(BNP, <18 pg/ml; ANP, <42pg/ml)in 42 pts(54%)and19 pts(24%),respectively. BNP level in NSVT was higher than PVC(74±87pg/ml vs.33±38 pg/ml;p<0.05). 2) Of 60 pts with successful CA, 38(63%)pts had a high BNP level, and it was significantly decreased after CA(48±63 vs.24±27pg/ml,p<0.001). I-VTs could be eliminated in right(n=48)and left ventricular outflow tract(8)or from the left sinus of Valsalva(22). No significant relationship was observed between the BNP level and I-VT origin or echocardiographic parameters. In 19(24%)pts, ANP level exceeded normal range before CA, but it did not significantly change after CA. 3) BNP level exceeded normal range in 5(83%)of 6 pts with unsuccessful CA. However, it was not significantly decreased after CA. 1)Plasma BNP level was elevated in >50% of patients with symptomatic I-VT. 2) A higher BNP level in NSVT than in PVC and a significant reduction of the BNP level after successful CA indicate that plasma BNP level may reflect abrupt change of wall tension by I-VT and that plasma BNP level may predict successful CA for symptomatic PVC.
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| 57P-1 EVALUATION OF ATRIOVENTRICULAR CONDUCTION AFTER NONSURGICAL SEPTAL REDUCTION THERAPY FOR HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY Pierre Dieuzaide, MD, Philippe L'Allier, MD, Laurent Macle, MD, Mario Talajic, MD, Marc Dubuc, MD, Denis Roy, MD and Bernard Thibault, MD. montreal heart institute, Montreal, PQ, Canada Background: Nonsurgical septal reduction therapy (NSRT) is a new and effective modality for the treatment of refractory hypertrophic obstructive cardiomyopathy (HOCM). Little is known about the atrioventricular (A-V) conduction changes occurring after NSRT. We prospectively evaluated the A-V conduction in patients undergoing NSRT for the treatment of HOCM. Methods: Thirteen consecutive patients with HOCM (7 female, 52±15 years) underwent an electrophysiological study (EPS) before and after NSRT in our institution. AH and HV conduction intervals, A-V Wenckebach (A-VW) and effective refractory period of the AV node (ERPAV) were measured. Results: Complete Infra Hissian block was observed in 3 patients(23%) after NSRT. In the other 10 patients, HV interval increased from 46±8 msec(range35–63 msec) before NSRT to 73±18 msec (range38–120 msec) after the intervention (P<0.05), the AH interval, A-VW and ERPAV remained unchanged after NSRT (AH: 85±20 msec VS 90±22 msec, p =NS; A-VW: 397±89 msec vs 412±81 msec, p=NS; ERPAV 340±120 msec vs 380±114 msec, p=NS).Seven of the 13 patients (54%) underwent pacemaker implantation after the procedure: 3 for complete Infra Hissian block, 3 due to major HV prolongation and 1 for late transient complete AV block.Conclusion: NSRT for HCOM lead to acute electrophysiological changes in the infra nodal conduction without affecting AV nodal conduction. These changes may be substantial necessiting permanent pacemaker implantation.
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| 57P-2 OPTIMAL AV-DELAY IN PACEMAKER PATIENTS: KAPPA 900® REGISTRY RESULTS P. Bloch-Thomsen1, A. Cuijpers2, P. Lamm3, G. Juchem4, for the Kappa 900 Registry investigators. KAS Gentofte, Hellerup1, Hillerod Hospital, Hillerod2, Bakken Research Center, Maastricht3, University Hospital Munich-Grosshadem4. Purpose: Many pacemaker (PM) patients (pts) have natural AV conduction times of >300 ms. The Medtronic Kappa 900® PM (K900) contains a Search AV algorithm (S-AV) that automatically searches for AV-Delays to uncover intrinsic ventricular activation (VS) when still intact. The effect of S-AV and PAV settings on maximizing %VS was determined.
Methods: In K900 registry, 95 investigators collected PM data from 1595 PM pts (54% males, 70±15 years, 66% SND, 80% dual chamber [DC] PM). %VS for S-AV ON vs OFF and PAV<150ms vs >150ms in DC pts, without complete AV block (AVB-) was calculated. Results: Overall %VS in 864 DC AVB- pts was 29%. In 81% of these pts S-AV was ON. VS>50% was seen in 223 pts (27%). Almost all (80–90%) pts with PAV
Conclusion: Extended P AV and S - AV activation seem to be effective in promoting intrinsic V activation.
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| 57P-3 SEARCH AV+: A NEW FEATURE TO PROMOTE INTRINSIC VENTRICULAR ACTIVATION Milasinovic, Goran, Sperzel, Johannes, Compton, Steven, Mead, Hardwin, Smith, Timothy W., Brandt, Johan, Haisty, Wesley, Bailey, J.Russell, Roelke, Marc, Simonson, Jay, Englund, Jennifer, Henk, Dieteren, Worldwide EnPulse Investigators. Clinical Center of Serbia, Belgrade, Kerckhoff Klinik, Bad Nauheim, Alaska Heart Institute, Anchorage, Sequoia Hospital, Redwood City, Washington University, St. Louis, Lund University Hospital, Lund, Wake Forest University, Winston-Salem, Mid-Carolina Cardiology, Charlotte, Arrhythmia and Pacemaker Consultants, West Orange, Cardiovascular Consultants, Ltd., Minneapolis, Medtronic, Inc., Minneapolis, Bakken Research Center, Maastricht. Search AV+ is a new algorithm in Medtronic EnPulseTM pacemakers offering the capability to search out to longer atrioventricular (AV) intervals in patients with intact/intermittent atrioventricular conduction, (maximum search limit of 350 ms). Purpose: The goal of the study was to assess the extent to which SAV+ minimizes unnecessary ventricular pacing. Methods. We compared the percent ventricular pacing with SAV+ ON to what it would have been with SAV+ OFF in 194 patients with indications for DDD/R pacing. SAV+ nominal values were required (PAV 150 ms, SAV 120 ms, maximal increase to AV 170 ms.). The patient cohort was defined by clinician assessment of patient conduction via a 1:1 AV conduction test. Results. At the one-month follow-up AV conduction was intact in 111/194 patients; SAV+ remained ON in 100 of them. The mean percent ventricular sensing in 111 patients with intact AV conduction for SAV+ ON was 76.3 versus SAV+OFF 2.8 (mean difference 73.5, range 0.0–99.9). Conclusion. The SAV+ algorithm substantially increases the frequency of intrinsic ventricular activation and decreases the amount of unnecessary pacing.
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| 57P-4 OUTCOME OF RIGHT VENTRICULAR BIFOCAL PACING IN PATIENTS WITH PERMANENT ATRIAL FIBRILLATION AND SEVERE DILATED CARDIOMYOPATHY DUE TO CHAGAS DISEASE: THREE YEARS OF FOLLOW-UP. Antonio Menezes Jr, MD; Humberto G. Moreira, MS; Murilo T. Daher, MS. Federal University of Goiás. Goiânia - Brazil. Studies have showed a right ventricular bifocal pacing beneficial effect, using two leads in the right ventricle. The aim was to evaluate the effect of this approach in Chagas disease(P) who have developed both severe dilated cardiomyopathy and chronic atrial fibrillation. 30 P and 52 ± 6 years (16male), AV block, and (NYHA) functional class III or IV were included. (P) underwent endocardial dual-chamber pacemaker(PM) implantation with one lead placed near the right ventricular outflow tract and the other in the apex. P were examined by echo, 24-hour Holter, and NYHA class data before and 3, 6, 12, 18, 24, and 36 months after CRT application. Compared to the baseline, the ejection fraction increased in the first months of CRT, the left ventricular end diastolic diameter decreased, all patients were downgraded to NYHA class I or II, and the complex ventricular arrhythmias decreased. However, the initial improvement could not be maintained and worsened after 6 months of CRT. A high mortality rate of 43.3% was observed during the first year, and only 23.3% of patients remained alive after 3 years. They underwent an electrophysiologic study, which revealed complex arrhythmias justifying implantable cardioverter defibrillator (ICD) implantation in six of the (P). In summary, the beneficial effects of right ventricular bifocal pacing could not be maintained beyond the first 6 months of CRT, likely due to the development of severe complex arrhythmias, which is a common part of the natural history of Chagas disease. Therefore, CRT combined with ICD treatment from the outset may be recommended for this patient group.
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| 57P-5 BRIGHT STUDY, INTERIM RESULTS: BIFOCAL PACING IN CONGESTIVE HEART FAILURE Jan C.J. Res*, Marcel J.J.A. Bokern, on behalf of the BRIGHT-Investigators, *ZMC_De Heel Waterland, NETHERLANDS Background: Bifocal right (BRIGHT) pacing is RV outflow tract and apex pacing as an alternative form of CRT in CHF patients. The BRIGHT study is ongoing randomized cross-over CRT pacing study in CHF pts and 29 pts are enrolled in this study. Pts characteristics are: age 68±9 years, 9 female/20 male, CHF-NYHA class 3,0 ± 0,3 (range 2,5–4); EF 23 ± 6% (<35%); QRS-width182 ± 19 ms (>120 ms). Methods: Minnesota quality of lifes score, LV ejection fraction (EF), 6min. walk and NYHA class were endpoints, measured before randomisation and after 3 months of back up pacing (VVI 40 bpm at RV Apex) or BRIGHT pacing. 17 pts had a follow up of minimum of 7 months and were analysed. 4 pts were excluded from study: 2 due to early death (<randomisation)and 2 pts had lead related problems. Results: The quality of life score tended to improve from 29 ± 21 to 21 ± 18 (p = NS) during BRIGHT pacing, and remained stable in the control patients. The EF was before randomisation 27 ± 9% and tended to be higher 36 ± 13% after during BRIGHT pacing (p=NS) and tended to be lower in the controls: 24±18%. The 6-min. walk test was a little increased after BRIGHT pacing vs. the control group: 486 ± 91 m vs. 446 ± 91 m (p=NS). Five patients could not tolerate reprogramming from bifocal BRIGHT pacing to the control pacing mode. Conclusion: In this small group of pts clear benefit was obvious in a few patients who could not tolerate spontaneous conduction after a period of BRIGHT pacing. Final conclusions cannot be drawn, but a tendency towards hemodynamic benefit of BRIGHT pacing is present in this small group of patients.
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| 57P-6 CHARACTERISTICS OF BIFOCAL PACING LEADS: RV APEX VS. OUTFLOW TRACT Jan C.J. Res*, Marcel J.J.A. Bokern, on behalf of the BRIGHT-Investigators, *ZMC_De Heel Waterland, NETHERLANDS. In 35 CHF pts with bifocal pacing as CRT 2 leads are used for resynchronisation: RV apex (Ap) and outflow tract (OT). Pts characteristics: age 68 ± 9 years, 9 female/26 male, NYHA class 2,9 ± 0,3; EF 24 ± 5%; QRS-width 182 ± 19 ms. Methods: Positioning attempts and complications were noted. Parameters were measured with the Era 300B at implant or via the STRATOS pacemaker at follow up: pacing threshold, R-wave amplitudes (wa) and impedances. Results: For positioning of the Ap and OT lead 1,6 ± 0,9 (1–4) vs. 2,1 ± 2,0 (1–10, p=NS) attempts were needed, with respectively passive fixation vs. active fixation (ELOX, Biotronik). In 2 pts advanced AV block occurred acutely during active fixation at the RVOT. Conduction recovered within 4 months. Positioning of the Ap lead caused ventricular fibrillation in one pt. Ap-wa is significant higher vs OT-wa: 22 ± 13 vs. 15 ± 8 mV (p<0,05). During follow Ap-wa remained stable (average 19 mV). The threshold at Ap was lower 0,5 ± 0,2 Volt vs. OT: 0,8 + 0,3 (p<0,005), which difference remained during follow up, but both showed a significant increase at 1 month: Ap increased to 1,2 ± 0,7 Volt and OT to 1,8 ± 1,1 (both p < 0,0001), and both declined at month 7 to Ap 0,9 ± 0,3 (n= 16, p=0,085) and OT 1,3 ± 0,4 (n=16, p=0,089). Pacing impedance was lower at the OT, mainly caused by the use of the active fixation lead at the OT vs. the Ap: 571±171 Ohm vs. 961±225 Ohm (p < 0,005). CONCLUSION: Striking differences were found between leads positioned in the OT vs Ap, 1) lower lead impedances and higher thresholds at the OT (due to lead design) and 2) unexplained higher R waves at the Ap compared to the OT.
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| 57P-7 BENEFICIAL HEMODYNAMIC EFFECTS OF LEFT INTERVENTRICULAR SEPTAL PACING IN PIGS. Marcel J.W.Grosfeld, Jan CJ Res, Dick HS Vos, Tjerk JM de Boer, BernhovenHospital, Erasmus MC Rotterdam, Biotronik Nederland, NETHERLANDS. Background: In search of alternative routes for left and right ventricular (RV) pacing the left interventricular septum (LIVS) is a good alternative: 1) it can be approached from the right side 2) it can be paced safely 3)it may give better hemodynamics than pacing on from any other RV position. Therefore in 11 pigs the hemodynamic effects of pacing at 3 single and 4 combined sites were compared: RV apex (RVA) vs, RV outflow tract (RVOT) vs. LIVS and combinations: RVA+RVOT, vs. RVA+LIVS vs. RVOT+LIVS vs. RVA+LIVS+RVOT. Methods: in 11 pigs a 11mm long screw (2 electrically active distal windings) was positioned at LIVS, from the right side. An atrial lead as well as RVA and RVOT leads were positioned for stimulation. Among others, positive and negative LV dp/dt, mean aortic pressure (MAP), flow and echocardiographic parameters, such as mitral insufficiency(MI) were recorded in all combinations, in the normal pig heart. Results: Hemodynamic parameters at LIVS tended to be better compared with RVA and RVOT in single site stimulation, for example: MAP was 65±16 mm Hg at LIVS vs RVOT 60±14 (p=0,10) vs RVA 58±16 mm HG (p=0,01). Pos dp/dt tended to be better at LIVS 1105±378 vs.1012± 342 at RVA (p=0,06), and also flow tended to be higher at LIVS 2,8±0,9 l/min vs. RVA 2,3±0,7 (p=0,08). Pacing at RVA produced more MI: 1±0,9 vs. LIVS: 0,3±0,3 (p=0,01). Conclusions: In 11 pigs hemodynamic parameters tended to be better with LIVS pacing compared to the other single pacing sites, especially compared tot RVA pacing. Furthermore any combination without RVA pacing is better then any combination with RVA pacing, especially with respect to the degree of mitral insufficiency.
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| 57P-8 SURFACE ECG VALIDATION OF EFFECTIVE PERMANENT HIS-BUNDLE PACING. M. Bortnik, E. Occhetta. A. Magnani. G. Francalacci, P. Devecchi, C. Piccinino. C. Vassanelli. Cardiology Division, Faculty of Medicine, Novara, Italy. Conventional right ventricular apical pacing may alter ventricular synchronism; alternative pacing sites have been proposed to maintain physiological ventricular activation. The ECG morphology of stimulated QRS is an important tool to assess the correct position of pacing lead. A prospective study performed in our Center aimed to evaluate the feasibility and the hemodynamic improvement of permanent direct His bundle pacing after atrioventricular node ablation in 16 patients with chronic atrial fibrillation and narrow QRS complexes, In 4 of them, during assessment of hisian pacing threshold, we observed different ECG patterns modifying pacing voltage: with a nominal output (3.8V–0.4msec) the paced QRS was similar to the spontaneous junctional escape rhythm, testifying hisian capture; an output voltage decrease resulted in a left bundle branch block paced-QRS morphology, suggesting the capture of only right muscular interventricular septum; a further decrease of stimulus voltage resulted in loss of ventricular capture. This ECG findings confirm that real His-bundle pacing was obtained during permanent daily pacing; the role of surface ECG in assessing the correct site of stimulation is essential.
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| 57P-9 HEMODYNAMIC CHECK OF PACING EFFECTIVENESS BY TRANS-VALVULAR IMPEDANCE M.G. Bongiorni, E. Soldati, G. Giannola, G. Arena, A. Barbetta*, F. Di Gregorio* Cardiothoracic Dept., University of Pisa; *MEDICO Clinical Research, Rubano (Padova); Italy Trans-valvular impedance (TVI) is measured between right atrium and ventricle with standard pacing leads. TVI fluctuations are recorded along the cardiac cycle, with a minimum value in telediastole (ED-TVI) and the maximum at the end of systole (ES-TVI). ED-TVI has been shown to be inversely related with the preload, while ES-TVI is insensitive to preload and changes progressively as a function of ventricular contractility. The TVI sensing system has been implemented in an experimental external stimulator (Ext Sophós, Medico, Italy) providing dual-chamber pacing, contractility-driven rate adaptation and beat-by-beat recognition of mechanical ventricular activation. The present study has tested the Sophós capture confirmation algorithm during pacemaker replacement in 10 patients. The stimulator compared the maximum TVI recorded in each cycle with the average maximum in preceding 8 cycles. In the presence of ventricular ejection, ES-TVI variability was restricted in the range of 70 to 130% of the reference values, while in the absence of capture the relative ES-TVI never exceeded 50%. A discrimination threshold set between 50 and 70% allowed selective recognition of pacing failure based upon cardiac hemodynamics and prompt automatic increase in pulse energy. The TVI system showed similar sensitivity to either paced or intrinsic ventricular activity, ensuring correct detection of fusion beats.
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| 57P-10 CORRELATION BETWEEN MAGNITUDE OF LEAD POLARIZATION AND EJECTION FRACTION IN PACEMAKER PATIENTS Roger A. Freedman, MD, Xiaozheng Zhang, Joseph Gallinghouse, MD, John Messenger, MD, Bruce Van Natta, MD, Seth Worley, MD, University of Utah, Salt Lake City UT, St. Jude Medical CRMD, Sylmar CA, Texas Cardiac Arrhythmia, Austin TX, Long Beach Memorial, Long Beach CA, Lancaster General, Lancaster PA. Pts with reduced LVEF and heart failure may have excess cardiac extracellular fluid, and in those with pacemakers excess fluid in myocardium surrounding pacemaker electrode may affect passive electrical properties of lead-heart interface. Pacemakers with AutoCapture feature provide measurements of lead polarization, caused by positive ions attracted to electrode by pacing stimulus. This study examines correlation between measures of heart failure (LVEF and NYHA class) and magnitude of polarization signal as measured by pacemakers with AutoCapture. Methods: 360 pts, age 74±13 years, 192 male, LVEF 52±13%, NYHA II-IV in 44%. The polarization signal amplitudes were obtained during the Evoked Response Sensitivity Test at implant. Results: Polarization signals were highly correlated with LVEF (r=0.2, p=0.005). An increase in LVEF of 1% predicted an increase in polarization of 0.25 mV. The correlation was independent of type of implanted lead. Similarly, measured polarization signals were lower in patients with higher NYHA class, but correlation was of borderline statistical significance (p=0.058). Conclusion:The magnitude of polarization artifact obtained from pacemakers with AutoCapture feature correlates with LVEF and NYHA functional class. Future studies are required to determine whether serial measurement of polarization signal amplitude is useful for monitoring progression of heart failure.
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| 57P-11 AN ACUTE CANINE MODEL FOR MONITORING VOLUME OVERLOAD BY INTRA-THORACIC IMPEDANCE Xiaoyi Min, Joe Florio, Peter Boileau, Todd Pavek, Chris Moulder, Gene Bornzin, Euljoon Park, Gabriel Mouchawar, St. Jude Medical CRMD, Sylmar, CA. Background: Early warning of fluid overload would help physicians managing CHF patients with ICDs or pacers. Several studies have shown that device based impedance monitoring was able to predict CHF admission. However, the relationship between LVEDP and intra-thoracic impedance (Z) has not been well established. In this study an acute volume overload model was created in canines. Z as well as LV, AP and PA pressures were monitored closely during pulmonary edema induction. Methods: In four canines the ventricular rate was controlled at 90 bpm. Z was measured between the ICD case and RV shocking coil while averaging over a respiration cycle. First the canine was volume loaded until the LVEDP exceeded 25 mmHg and allowed to stabilize. Then loading continued until the LVEDP reached about 35 mmHg. Results: During volume overloading Z monotonically decreased. The time durations from the start of fluid loading to the pulmonary edema were 213 ± 23 minutes, while Z decreased 10% from the baseline in 96 ± 42 minutes. A 10% drop in impedances corresponded to a 20 ± 6 mmHg increase in LVEDP. The pulmonary edema was determined by rales and pink watery fluid from the mouth or nose. Conclusions: RV volume overload through femoral vein access was successful in creating pulmonary edema acutely. LVEDP was linearly related and correlated to Z from the onset of overloading to a 10% Z drop (R=0.96 ± 0.03, Slope=_0.33 ± 0.07 ohm/mmHg).
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| 57P-12 WHICH IS THE BEST CLINICAL VARIABLE TO DETERMINE THE DOMINANT SENSOR IN DDDR PACEMAKERS? M.Gulizia, M.Francese, (1)E.Moro, (2)M.Comito, (3)M.Landolina, (4)A.Vicentini, (5)G.Raciti, (6)L.Padeletti. Osp S.Luigi-Currò,CT, Italy; (1)Osp S.M. dei Battuti,Conegliano, Italy (2)Osp Jazzolino,VV, Italy; (3)Policlinico S.Matteo,PV, Italy; (4)Casa di cura Pederzoli, P.del Garda, Italy; (5)Guidant,MI, Italy (6)Az Osp Careggi,FI, Italy; AIM. In rate responsive(DR) pacemakers(PM) with dual sensor (accelerometer(XL) and minute ventilation(MV)), search for the patient characteristics that best predict which sensor gives the dominant contribute to rate response. METHODS: 53 pts were implanted with dual sensor pacemaker INSIGNIA PLUS, Guidant. The device diagnostics (ACTIVITY LOG) is capable of storing on a daily basis the patient percentage of physical activity and a detailed 24-hour trending function of each sensor contribute. Trending retrieved at 1 month post implant has been used to calculate the mean difference between the 2 sensors curves (XL-MV), which indicates a dominant contribute of XL when XL-MV>0 and of MV when XL-MV<0. A multivariate regression investigated the dependence of XL-MV from the following variables: age, NYHA class, physical function score of SF-36 questionnaire (PF-SF36) and mean daily percentage of physical activity (A%).RESULTS: XL was prevalent in 23/53 pts (age 66,9±12,4; PF-SF36 81,8±14,5; A% 8,9±3; nyha I in 70%); and MV in 30/53 (age 73±8,1; PF-SF36 72,8±16,5; A% 5,2±2,6; nyha I in 33%). The multivariate (R=0,61 p<0,01) showed significant differences for A% (p<0,01; beta=0,56) and NYHA class (p<0,05; beta=-0,24).CONCLUSION. a) MV sensor contribute is prevalent in the majority of pts, b) daily percentage patient activity, available from PM diagnostics, predicts better than other clinical parameters which sensor will give the dominant contribute in determination of the rate response.
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| 57P-13 SENSOR OPTIMIZATION IMPROVES EXERCISE CAPACITY WITHOUT CHANGING QOL Ayten Erol Yilmaz, Raymond Tukkie, Tim Schrama, Jan Tijssen and Arthur Wilde. Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands Purpose of the study: Programmable pacemaker sensor features are frequently used in default setting. Limited data are available about the effect of sensor optimalization on exercise capacity and quality of life (QOL). Influence of individual optimalization of sensors on QOL and exercise tolerance was investigated in a randomized, single-blind study in VVIR, DDDR or AAIR pacemakers.
Methods: Patients with Results: Twenty six patients in group 1 and 23 in group 2 were included (mean age 60 ± 16.8 years) with similar baseline characteristics. Individual optimalization significantly increased maximum heart rate (+9 ± 16.1, p=0.023) and exercise capacity (+2.3 ± 3.8 METS, p=0.044). QOl-q dimensions were not significantly changed between the groups. Conclusion: After 1 month of individual optimalization of rate response pacemakers, exercise capacity was improved and maximum heart rate increased, although QOL were unchanged.
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| 57P-14 NON-INVASIVE ASSESSMENT OF MYOCARDIAL CONTRACTILITY BY THE FORCE-FREQUENCY RELATION (FFR) EMPLOYING IMPLANTED PACEMAKERS H.Bondke,A.Borges,S.Petersen*,T.Walde,G.Baumann Humboldt-University, Charité Campus Mitte, Cardiology, Berlin, Biotronik*, Erlangen, Germany Background: Increasing heart rate (HR) is followed by a positive slope of the myocardial contractility (FFR). FFR is a determinant of inotropy and is mostly measured in strips or invasive. In this study a pacemaker (PM) was employed to increase HR non-invasive. Contractility was assessed non-invasive by the Tissue Doppler based determination of the Isovolumic Myocardial Acceleration (IVA). The aim was to evaluate the feasibility of IVA and of a new index from the Intracardiac Impedance (ICZ) signal, measured by the PM, to determine the FFR as a result of the increased HR by the PM. Methods: Sixteen patients with normal EF and implanted with a PM (Inos2CLS, Biotronik) were examined. At DDD paced HR of 80, 100, 120/min, IVA of the LV free wall and the apical septum was measured. Simultaneously, a continuous recording of the ICZ curve was performed via the PM. The max. acceleration of ICZ change during ventricular contraction (ICZacc), and the time between the ventricular pace and ICZmax (tZM) was determined and correlated with IVA. Results: HR (/min) 80 100 120 co-occurred with: (*p< 0.05) IVA septal (m/s2.) 1.2±0.7 1.7±0.6 2.2*±1.1 IVA left-lateral (m/s2) 1.7±0.9 2.1±1.0 2.4*±1.3 ICZacc: (kOhm/s2) 3.7±2.4 5.9±2.5 6.6*±4.4 tZM (ms) 259±91 226±82 185*±68 Correlations: septal IVA and ICZacc (R=0.82, p=0.0005) and septal IVA and tZM (R=-0.51, p=0.01) Conclusion: A positive FFR can derived from the frequency dependence of both IVA and ICZ. The pacemaker itself can realise HR increase and ICZ determination. Therefore non-invasive assessment of myocardial contractility by the FFR in patients with implanted pacemakers is possible.
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| 57P-15 A NEW PACEMAKER FUNCTION TO PERMANENTLY FOLLOW- UP PATIENT'S CLINICAL STATUS. Philippe Deutsch, Pascale Ducloux°, Cyrille Cassef°. General Hospital, St Malo, °ELA Medical, Le Plessis-Robinson, France. Rate-responsive pacemakers provide meaningful information from sensors, which may be interesting to follow-up patient's physical status. The objective of this new function is to help the physician to analyze the evolution of the physical status of paced patients in-between the visits. Methods. ELA Medical pacemakers (PM) feature accelerometer and minute ventilation sensors. Cross-check between both sensors allows the calculation of the activity duration (Ad). The accelerometer reflects the mean intensity of physical activity (Ai), and mean minute ventilation (MV) is calculated at rest and during activity phases. We analyzed the evolution of the physical status of 22 patients (12 males, 75±10 y. old) implanted with a Talent 3 DR PM (ELA Medical, France). Pacing indications were for AV block (n=13), Brady-Tachy syndrome (n=7), Sinus node dysfunction (n=2). PM data were retrieved at pre-discharge (PD) and at 1, 2 and 3 months follow-up (FU), Results. Activity indexes increase shortly after PM implantation to remain stable during follow-up (Duration: 3.8 hours/day at PD to 4.8 during FU: +28%, and intensity: 7.1 mg to 7.9: +15%), while MV parameters do not appear to be affected by PM implant.
Conclusions. 1. Less than 1 month is necessary to retrieve a daily-life activity after PM implant; 2. PM have no significant effect on MV in patients implanted for conduction disorders.
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| 57P-16 ADENOSINE-INDUCED SYNCOPE: PREVALENCE AND CHARACTERISTICS M. FATEMI MD, A. PERENNES MD, ML BOREL MD, C L'Her MD, JJ BLANC MD. Brest University Hospital, Brest-France. Introduction: Occurrence of ventricular pause of more than 6 seconds following administration of 20 mg bolus of intravenous adenosine (ATP test) has been observed in a relatively high percentage of patients (pts) with unexplained syncope. However, these results have been reported in a relatively limited number of pts in only 2 series. The aim of our study was to assess the prevalence of this entity and pts' characteristics with positive ATP test in a larger single-center study. Methods: Pts were recruited consecutively based on following criteria: 1) at least one syncopal episode defined according to ESC guidelines, 2) no diagnosis after usual work-up, including systematic clinical evaluation, orthostatic hypotension, ECG and when necessary, carotid sinus massage, electrophysiological study, and tilt table test. ECG was continuously monitored during and after ATP test and a ventricular pause longer than 6 seconds was considered as abnormal. Results: Among the 109 pts with unexplained syncope, 7 had a positive ATP test (6.4%). When compared to the negative ATP group, pts with positive ATP test had the following characteristics: female predominance (85.7% vs 49.5%, p=0.07), significantly older age (75.4+/–11.8 vs 56.1+/–17.8 years, p<0.006), more syncopal episodes during life (6.14 vs 4.54, p=NS), older age at the first episode (63.6 vs 47.4 years, p=0.05). Prodromal symptoms and traumatic consequences of syncope were not significantly different between the 2 groups. Conclusion: Although rare, ATP-induced syncope accounts for 6% of pts with unexplained syncope after a complete evaluation. Women older than 70 years represent the population in whom the ATP test had the highest likelihood of being positive. Treatment by pacemaker remains to be evaluated.
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| 58P-1 MORPHOLOGICAL EFFECTS OF RADIOFREQUENCY ON CORONARY STRUCTURES R.G. Demaria*, T.K. Leung, P. Pagé, M. Carrier, B. Albat*, L.P. Perrault. Montreal Heart Institute, Montreal, Canada and *Arnaud de Villeneuve Hospital, Montpellier, France Purpose of the study: Surgical radiofrequency (RF) ablation is widely used during surgery for the treatment of atrial fibrillation. The purpose of this study was to determine the morphological effects of RF on coronary structures Methods: In a porcine model, three epicardial radiofrequency lesions (20 Watts, 20 seconds duration) 2 cm in length each, were created 1, 5 and 10 mm away from the left anterior descending artery. Gomori's Trichrome and Hematoxylin Eosine Safran (HES) staining were used. Results: Microscopic examination showed a well deliminated RF effect area on the myocardium. The depth of lesions was 5mm ± 1mm. At the center of the RF lesion, myocardial cells were coagulated and necrotic. They were surrounded by edema and hemorrhage. When located inside the RF effect area, the arterial wall was seriously damaged with disruption of the endothelium and necrosis of smooth muscle cells. Conclusion: Radiofrequency may induce coronary damages when applied less than 5 mm from the artery. Caution must be exerted during left atrial RF application due to the proximity of the circumflex artery.
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| 58P-2 HEMOSTATIC CHANGES DURING ELECTROPHYSIOLOGIC STUBY AND RADIOFREQUENCY CATHETER ABLATION P. Parizek, L. Haman, J. Maly*, M. Pecka*, J. Bukac**, P. Stransky**, M. Hodac*. M. Pleskot 1st and *2nd Dept. of Internal Medicine, **Dept. of Medical Biophysics, University Hospital, Hradec Kralove, Czech Republic Aim: Thromboembolic complications are described in about 1% of the patients undergoing radiofrequency ablation (RFA). The aim was the study of chosen hemostasis activation markers during electrophysiologic study with consequent RFA. Methods: 63 patients were studied prospectively during EP studies (EPS) with RFA for SVT. Blood samples were drawn before the insertion of sheaths (T0), at the end of EPS (T1) and 30 min after completion of RFA (T2). To study coagulation, fibrinolytic, and platelets activation we measured concentrations of thrombin-antithrombin III (TAT), D-dimers (DD), plasminogen inhibitor activator (PAI-1), plasminogen tissue activator (tPA), and circulating platelet aggregates (CPAi). Results: Levels of DD increased from 0.30±0.20 mg/l at T0 to 0.44±0.25 mg/l at T1 (p<0.001) and to 0.87±0.74 mg/l at T2 (p<0.001), TAT levels increased from 12.90±12.83 µg/l at T0 to 36.07±15.59 µg/l at T1 (p<0.001) and decreased to 28.85±13.14 µg/l at T2 (p<0.001). PAI-l concentration decreased from 37.49±23.20 µg/l at T0 to 29.74±14.00 µg/l at T1 (p<0.001) and to 28.13±12.86 µg/l at T2 (p=0.07). Dependance of concentration of DD at T2 vs. T1 on the number of RF energy applications (p<0.001, R2=0.462) was found. Marked platelet activation (CPAi 0.59±0.29) was observed from the start of the procedure without changes during the procedure. Conclusions: Our results confirmed activation of hemostasis during EPS and RFA. Dependance of concentration of DD on the number of RF energy applications was found. Our results support eligible antithrombotic prevention in patients indicated for EPS and RFA. Supported by IGA MZ CR - NA 6603-3
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| 58P-3 THE DIFFERENT PERFORMANCES OF COMMERCIALIZED RADIOFREQUENCY GENERATORS M Fukuta, T Iwa, S Fukuta, I Kato, Y Suzuki, Y Wakida, T Ito. Aichi Medical University, AICHI, JAPAN It is not well known whether different radiofrequency generators (RFC) have the same performance. We studied the difference among three commercialized RFG (A, B and C) by ablating tissue with the same catheter in vitro. Methods. The same 7F ablation catheter which had both a thermister and thermocouple was positioned perpendicularly or horizontally to the tissue and connected sequentially to RFGs. A total of 240 sites from 18 swine hearts were ablated in a tissue bath with a temperature controlled output (60C) under external convective cooling by fluid flow. The size of the tissue damage was carefully examined and statistically analyzed. The representative results are presented below. Conclusions: There was a great difference in the performance, including the frequency of pop, among the commercialized RFG when the temperature control mode was selected.
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| 58P-4 DOES PROLONGATION OF PULSE DURATION INCREASE DAMAGE IN CATHETER ABLATION T Iwa, S Fukuta, M Fukuta, I Kato, Y Suzuki, Y Wakida, T Ito. Aichi Medical University, AICHI, JAPAN The pulse duration of 60 second is mostly selected in human catheter ablation procedure. We studied whether the lesion volume and depth could be increased safely by the prolongation of pulse duration under various conditions in vitro. In a jet bath, 160 points on 12 swine hearts were ablated with a 4mm tip (4MT) or a 8mm tip (8MT) catheters. A temperature control output of 60 Cersius was selected and the energy was delivered for a total of 60, 90, or 120 seconds (D60, D90, D120). The orientation of the 4mm tip ablation catheter was kept perpendicular or horizontal, and the catheter and tissue were exposed to a constant external flow at a rate of 0, 20, 30 and 55 cm/s. Results: Compared with D60; 1) the D90 did not increase the lesion volume nor depth with C4. 2) The D120 increased the lesion volume and depth in some conditions with C4, however, the increasing rate were small (< 30%). 3) D90 and D120 increased the lesion volume and depth 50% to 100% at a fluid flow rates > 20cm/s. 4) an occurrence of pop was observed only with D120. Conclusions: With 4MT D60 is optimal, however, D90 are useful and safe with 8MT when larger lesion are necessary.
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| 58P-5 RELATIONSHIP BETWEEN POWER, TIP TEMPERATURE, AND TISSUE TEMPERATURE DURING ABLATION WITH A COOL-TIPPED CATHETER Gregory Keith Bruce, Douglas L. Packer Mayo Clinic, Rochester, MN PURPOSE: Guidance of energy delivery during ablation with a cool-tipped catheter is difficult since catheter lip temperatures are cooled by continuous flow. The delivery becomes power controlled. The relationship between power, tip temp, and tissue temp is unknown. METHODS: 9 dogs underwent 101 ablations at the PV ostia with a closed-loop, cool tipped (D5W irrigated) catheter. 5 to 45 watts were delivered over 120 seconds. Tissue temp was recorded by epicardial thermocouples. RESULTS: Tip and tissue temp were markedly discrepant with increasing disparity seen with increasing power. Any power delivery over 5 W produced tissue temp > 55°C. Power >25 W tended to result in tissue temp > 70°C.
CONCLUSION: This study demonstrates a quantitatively greater than expected discrepancy between tip and tissue temp with closed loop, cool tip ablation. Tip temp is unhelpful with guiding power delivery. Power-tissue temp correlation however may provide some guidance, although serious excessive tissue heating could occur.
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| 58P-6 LEFT HEART LASER CATHETER APPLICATIONS Weber HP, CCEP-Center Munich, Munich, Germany Safety and effectiveness of laser applications in the left heart were assessed. Laser catheter ablation was attempted during 39 procedures in 31 patients (pts) aged 37–87, average 63.2 years (f=18, m=13), with drug resistant paroxysmal (n=8) or persistent (n=13) atrial fibrillation (Afib), ventricular tachycardia/extrasystole (n=2/2), and left free wall accessory pathways (n=2). Left heart catheterisation was performed by using a long preshaped sheath adapted for targeting the foramen ovale. The guide wire was replaced by an optical fibre and laser puncture was performed (Nd:YAG, 1064nm, at 3–5 W/2–3 s). During continuous heparinized saline flushing (5000 IU/l, 3–5 ml/min) the laser catheter was easily manipulated with a preshaped and steerable sheath until brought in a stable end-on position upon the area of interest. During the 1–15 laser applications per pt. (average=5.3) at 10–25 W/5–420 s, 50–3750 J, saline flushing increased automatically to 10–30 ml/min. With the onset of irradiation a gradual abatement of electrical potentials was seen in the local electrograms. They always recovered when irradiation times were shorter than 5 s. In general, in pts with Afib laser applications were aimed at left atrial areas, adjacent to the inflow of the pulmonary veins. In addition, in 7 pts with persistent Afib 2–5 right atrial targets were irradiated. Procedure duration ranged from 20–369, average 102 min, X-ray exposure times were 4.8–407, average 12.8 min. Arrhythmias were abolished acutely in all except in one with persistent Afib despite repeated procedures. Complications were not encountered. In 7 pts drug regimen is still needed (e.g. Betablockers) due to hypertension or congestive heart failure (follow-up >4.3 years). The laser method is a safe and highly effective alternative for catheter ablation of arrhythmias in the left heart.
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| 58P-7 Combined Optical and Immunohistochemical Imaging of The Developing Conduction System of The Rabbit Heart F Rothenberg, MD: VP Nikolski, PhD, M Waianabe, PhD and IR. EJimov, PhD. Case Western Reserve University, Cleveland, OH We applied optical mapping with voltage-sensitive dye and anti-neurofilamcnt 160 (NF 160) immunostaining to investigate structural and functional development of the entire conduction system in the rabbit heart. Methods: Mid-gestation (day 14) New Zealand rabbits were anesthetized and the embryos harvested. Isolated hearts (n=4) were stained in Tyrode's solution containing di-4-ANEPPS (20 µm). Spontaneous action potentials were mapped with a Hamamatsu 16×16 photodiode array (sampling rate 5 KHz). The hearts were sectioned and triple-labeled with antibodies against NF 160, anti-sarcomeric actin, as well as anti-nuclear DAPI stain. Every Other slide was stained with hematoxylin and eosin. Results: In the post-septated embryonic rabbit heart, the ventricles in the ventral view activated first at the apex, excitation spread rostrally along the inter ventricular groove, and then laterally to stimulate each ventricle. Ventricular activation was completed in 1.0 msec (conduction map in the upper panel). NF 160 labeled cells were in anatomic locations consistent with conduction system cells (lower panel). Confocal microscopy revealed co-localization of ami-sarcomenc actin and NF 160.
In frontal sections, continuity at the atnoventricular node-His-Purkinje region is not evident.Conclusions: Global activation sequences of the post-septated rabbit embryonic heart as detected with optical mapping reveals "mature" ventricular activation defined by an "apex-to-base" pattern. NF 160 labeling of these hearts did not show clear continuity of labeling at the level of the atrioventricular node-His-Purkinje pathway, suggesting mat primary conduction along the His-Purkinje pathway occurs either with the aid of other cell types, or conduction system cells that do not express NF 160.
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| 58P-8 AN INTEGRATED MODEL OF CARDIAC EXCITATION AND CONTRACTION N. P. Smith, M. L. Buist and A.J. Pullan Bioengineering Institute, University of Auckland A coupled cellular model of cardiac excitation-contraction-metabolism is embedded within an anatomically realistic finite element model of the cardiac ventricles, which is further embedded within a realistic torso model. At the cellular level, a recent model of myocyte metabolism is coupled to an existing excitation-contraction model via calcium transients and the metabolites ATP, ADP and inorganic phosphate. This cellular model of cardiac excitation-contraction is embedded in an anatomically accurate two-dimensional transverse cross-section of the cardiac ventricles and human torso. Waves of activation and contraction are induced by the application of physiologically realistic boundary conditions and solving the equations of finite deformation and bidomain equations on a deforming finite element mesh. Body surface potentials are calculated from this activation sequence by solving Laplace's equation in the passive surrounding tissues.The importance of cardiac deformation the on electrical activity induced by contraction is demonstrated in both single cell and tissue models. Action potential duration is reduced by 7 ms when the single cell model is subjected to a 10% contraction ramp applied over 400 ms. In the coupled electro-mechanical tissue model, the T wave of the electrocardiogram is shown to occur 18 ms earlier when compared to an uncoupled excitation model. Ischemia is induced by lowering pH, increasing extracellular potassium concentration, and reducing the rate of oxidative phosphosphorylation regionally in the tissue model. The relationship between electrocardiogram morphology and the geometry of the ischemic region is demonstrated.
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| 58P-9 DEFIBRILLATION EFFECT FOR INTRAVENOUS ADMINISTERING NIFEKALANT IN PATIENTS WITH OUT-OF-HOSPITAL VENTRICULAR FIBRILLATION Masaki Igarashi, Nariaki Uno, Tadashi Fujino, Keishi Sugino, Kenichirou Sasao, Yoshifumi Okano, Kenzaburou Kobayashi, Katunori Yoshiwara, Nobuya Koyama, CRITICAL CARE UNIT, TOHO UNIVERSITY HOSPITAL, Tokyo, Japan Purpose : Nifekalant(NF) is pure K channel blocker that developed in Japan, and has an effect for refractory ventricular arrhythmias. We investigated whether NF affect to defibrillative effects for out-of hospital ventricular fibrillation. Method : Subjects were 20 patients (male femaleé6Ô average 56±16 years/old) transferred to our hospital failed defibrillation in out-of-hospital. We examined as follows; serum sodium and potassium, PH and base excess in arterial blood, time from telephone call to hospital arrival. NF was give as a maintenance administration followed to a dose of 0.3û/û in Group N, and lidocaine was given at a bolus dose of 2mg/kg in Group C. Defibrillation was performed from an energy of 200 joules to 360 joules. Result : Group N was 8 patients, and group C was 12 patients. Five of eight patients in Group N had successful defibrillation and admitted to Critical Care Center, in contrast to only 2 of 12 in Group C (p<0.05). One patient in Group N could be discharged from hospital without neurological deficits. However, 4 in Group N and 2 patients died in hospital. There were no significances among serum sodium and potassium, PH and base excess, and time from telephone call to hospital arrival. Conclusion : NF has a potency defibrillate out-of-hospital VF.
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| 58P-10 DEFIBRILLATION OF PEDIATRIC PROLONGED VF: ADULT OR ATTENUATED DOSE? Robert A Berg (1); Fred W Chapman (2); Marc D Berg (1); Ronald W Hilwig (1); Isabelle Banville (2); Robert G Walker (2); Richard C Nova (2); and Karl B Kern (1). From (1)University of Arizona, Tucson, AZ and (2)Medtronic Physio-Control, Redmond, WA Weight-based monophasic defibrillation shocks are standard therapy for VF patients <8 years old. Special attenuating electrodes allow an adult automated external defibrillator to deliver an escalating energy sequence (50,75,86 J) of biphasic shocks already shown experimentally to be highly effective for resuscitation. We compared this approach to standard adult biphasic dosing. Piglets of 14 and 24kg (24 of each) were fibrillated for 7 minutes. LIFEPAK defibrillators delivered monophasic damped sine shocks of 2,4,4 J/kg (M) via pediatric-sized pads, biphasic shocks of 50,75,86 J (B50) via the same pads, or 200,300,360 J (B200) via adult-sized pads. Resuscitation was attempted with the pediatric BLS protocol from 7 to 20 minutes, then the pediatric ALS protocol to 27 minutes. B50, M and B200 shocks delivered 13±0, 24±1 and 38±2 A of peak current, respectively. The LV ejection fraction measured at 4 hours was lower than baseline by 11±7%, 32±11%, and 34±5% for B50, M, and B200 groups. More B50 piglets (13/16) survived to 24 hours with good neurological scores than M (5/16, p=0.011) or B200 piglets (4/16, p=0.004). Attenuated biphasic shocks resulted in superior outcome compared with either adult biphasic dosing via adult pads or the recommended monophasic weight-based dosing via pediatric pads. This supports the use of attenuating electrodes with adult biphasic automated external defibrillators for children in VF.
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| 58P-11 EFFECTS OF MONOCLONAL ANTIBODY AGAINST CARDIAC 21-ADRENOCEPTOR ON CARDIAC ELECTRIC AND MECHANICAL ACTIVITIES IN ADULT RATS RongFeng-Bao1 XinChuen-Yang1 Lin-Zhang1 BoWei-Wu2 XiangLi-Cui2 RongRui- Zhao2 1 Heart center, Beijing ChaoYang hospital Affiliated to the Capital University of Medical Sciences, BeiJing 100020, China 2 Department of Physiology, Shanxi Medical University, Taiyuan 030001 Background: It was previously demonstrated that the monoclonal antibody MAb M16 raised against the second extracellular loop (197–222) of the ß1-adrenoceptor (ß1-AR) had an agonist-like activity, and was able to significantly increase the beating frequency of the cultured neonatal rat cardiomyocytes. However, it remains to be elucidated that the effect of the monoclonal antibody on L-type ca++ channels of cardiac myocytes, the contractile force of papillary muscles, and the intracellular calcium transient in adult rats. Methods: In the present experiment, the effects of MAb M16 on L-type Ca++ channels were studied using the whole cell recording of patch clamp in ventricular cells of adult rats. The effects of MAb M16 on cytosolic Ca2+ transients were recorded using a dual-excitation fluorescence imaging system, with Fura-2 as the fluorescent probes. The mechanical effect of MAb M16, were examined by the peak contraction of adult rat papillary muscles. Results: MAb M16 was able to cause a dose-dependent decrease of basal Ica of myocytes in adult rats. Agonist isoproterenol could partially counteract the inhibitory of MAb M16. MAb M16 suppressed the intracellar Ca2+ transient. MAb M16 decreased the peak tension of contraction of papillary muscles in adult rats significantly. Preincubating of MAb M16 with the H26R peptide resulted in the disappearance of the inhibitory effects by antibody. Conclusions: The monoclonal antibody MAb M16 had inhibitory effects on cardiomyocytes of adult rats.
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| 58P-12 EDROPHONIUM INDUCED RIGHT VENTRICULAR OUTFLOW TRACT TACHYCARDIA Hitoshi Hachiya, Karl-Heinz Kuck, Yasuteru Yamauchi*, Kazutaka Aonuma*, Allgemeines Krankenhaus St. Georg, Hamburg, Germany *Yokosuka Kyosai General Hospital, Kanagawa, Japan Background: Idiopathic right ventricular outflow tract tachycardia(RVOT-VT) generally occurs when sympathetic nervous activity is increased; however, some RVOT-VTs occur when parasympathetic nervous activity(PNA) is increased. Methods: 1) Of 101 consecutive patients studied with RVOT-VT, 5 patients(4.9%) presented with RVOT-VT occurring during the nighttime. Autonomic nervous balance during daily activities has been studied by analyzing heart rate variability(HRV) obtained from Holter recordings. 2)Electrophysiologic studies: Standard programmed ventricular stimulation, ventricular pacing, and drug provocation were performed to induce RVOT-VT.RVOT-VT origin was confirmed by endocardial catheter mapping. Results: 1) The number of ventricular premature contractions(VPCs) was 6649±4472/day, and the averaged %VPCs during the nighttime from 8p.m. to 8a.m. was 74.4±14.3%. In the analysis of HRV, high frequency(HF) power increased progressively toward the appearance of VPCs, and low frequency/HF ratio did not show significant changes during a 24-hour period. 2) Not even a single beat of RVOT-VT could be induced by programmed ventricular stimulation, ventricular pacing, intravenous(IV) isoproterenol infusion, or IV adenosine triphosphate. RVOT-VT could only be induced by IV injection of 5 mg edrophonium(anticholinesterase agent) in all 5 patients. 3) RF application eliminated RVOT-VT and VPCs in all 5 patients without complications. Conclusions: 1) Edrophonium facilitates the induction of RVOT-VT in this type of patient. 2) These results suggest that PNA may play an important role in the appearance of VPCs and RVOT-VT in this type of patient.
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| 58P-13 INTEREST OF ELECTROPHYSIOLOGICAL STUDY AFTER ISOPROTERENOL B Brembilia-Perrot, I Muhanna. A Terrier de la Chaise, P Louis, O Claudon, M Nippert, M Andronache, E Aliot. A Abdelaal, Y Al Saleh, H Belhakem, E Khaldi. Cardiology, CHU of Brabois, Vandoeuvre, France The purpose of the study was to evaluate the results of electrophysiologic study (EPS) after isoproterenol in patients with syncope and negative EPS in control state. Methods: EPS was performed in control state and after isoproterenol in 238 patients, with syncope, negative EPS in control state; 33 had exercise-related syncope; 95 had heart disease (HD). Results: after isoproterenol, SVT was induced in 29 patients, VT in 31; one had SVT and VT; infrahisian AV block occurred in 2 patients, vasovagal reaction in 30. SVT was more frequent in patients without HD (20) than in those with HD (9); VT was more frequent in patients with HD (23) than in those without HD (8). There was no relationship between positive isoproterenol testing and exercise-syncope at (18/33 vs 74/195). VT Induction in patients with myocardial infarction were at high risk of sudden death (6/14). In conclusion, EPS should be repeated after isoproterenol, in patients with negative study in control state and with syncope related or not to exercise. Arrhythmia is identified as syncope cause in 39% of them.
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| 58P-14 CARVEDILOL IMPROVES VENTRICULAR ELECTROPHYSIOLOGY IN HEART FAILURE E.M. Kanoupakis MD, E.G. Manios MD, H.E. Mavrakis MD, P.G. Tzerakis MD, D.C. Kambouraki MD, N.C. Klapsinos MD, D. Arfanakis MD, Panos E. Vardas MD,PhD Department of Cardiology, Heraklion University Hospital, Heraklion, Crete, Greece. Purpose: We evaluated the effects of carvedilol on ventricular refractoriness and repolarization, in patients with congestive heart failure (CHF). Methods: We studied 11 patients with idiopathic dilated cardiomyopathy, presenting complex ventricular arrhythmias at Holter. Right ventricular effective refractory period (VERP) at 600,500 and 400 ms as well as monophasic action potential duration (MAPd90) at a drive cycle length of 500 ms, were measured before and after carvedilol treatment for 4–8 weeks. A 24-hour Holter monitoring test was performed before and after active carvedilol therapy. Results: VERP at 600 ms changed from 227±10 ms to 244±8 ms (p=0.04), VERP at 500 ms changed from 220±9 ms to 235±12 ms (p=0.01) and VERP at 400 ms changed from 213±7 ms to 229±11 ms (p=0.02). MAPd90 increased from 199±16 ms to 219±17 ms after treatment (p<0.05). Carvedilol significantly reduced total ventricular premature contractions from 283±66 to 121±44 per hour (p<0.01) and episodes of non-sustained ventricular tachycardia from 17±8 to 3.4±4 per day, (p<0.01). Conclusion: Our results suggest that carvedilol prolongs ventricular refractoriness and repolarization in patients with CHF, while reducing premature ventricular activity.
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| 58P-15 ISOPROTERENOL INFUSION FOR THE DIAGNOSIS OF SYNCOPE IN MYOCARDIAL INFARCTION. B Brembilla-Perrot, I Muhanna, A Terrier de la Chaise. P Louis, O Claudon, M Nippert, M Andronache, E Aliot, A Abdelaal, Y Al Saleh, H Belhakem, E Khaldi. Cardiology, CHU of Brabois. Vandoeuvre, France. The purpose of study was to evaluate the results of electrophysiologic study (EPS) after isoproterenol in patients with myocardial infarction (MI), syncope and negative EPS in control state. Methods: 48 patients, aged 58±19 years, with syncope, MI. no arrhythmia had negative EPS in control state; 5 had exercise-related syncope; EPS consisted of study of AV conduction, programmed atrial and ventricular stimulation ; study was performed in control state and after isoproterenol. Results: EPS remained negative in 25 patients ; VT was induced in 14 patients ; one had supraventricular tachyarrhythmia (SVT) and VT; 3 had SVT ; 2 had infrahisian AV block and 3 had vasovagal reaction. Patients with isoproterenol-induced VT and those without VT differed (p <0.05) by a lower LVEF (34±8% vs 48±15), a higher incidence of exercise-related syncope (4 vs 1), a higher risk of sudden death (6/14 vs 0/34) (follow-up 3±1). In conclusion, electrophysiologic study should be repeated after isoproterenol infusion, in patients with MI, to detect an arrhythmia in 49% of them. Patients with VT are at high risk of SD.
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| 58P-16 CAUSES AND PROGNOSTIC FACTORS OF SYNCOPE IN POSTMYOCARDIAL INFARCTION B Brembilia-Perrot, C Suty-Selton, MD, A Terrier de la Chaise, P Louis, O Claudon, B Popovic, M Nippert. N Sadoul, H Blangy, H Beihakem Cardiology, CHU of Brabois, Vandoeuvre, France The purpose of the study was to evaluate the prognostic factors of syncope in 232 patients with myocardial infarction (MI) Methods: LVEF evaluation, electrophysiological study were systematic. Results: LVEF was < 40% in 124 patients (group I), > 40% in 108 (group II). VT was induced in 47 group I patients, 17 group II patients (p< 0.01); ventricular flutter/fibrillation (VF) in 26 group I patients, 19 group II patients (NS); 23 group I patients. 35 group II patients (NS) had other causes. After 4 years ±2, cardiac mortality was 1) in group I 49% in patients with VT, 31% in those with VF, 6% in those without VT/VF, 2) in group II 11% in patients with VT, 5% in those with VF and 4% in those without VT/VF. VT, VF, LVEF < 40% were predictors of cardiac mortality, VT. LVEF < 40% predictors of sudden death (SD). Conclusion: only patients with MI, syncope, LVEF < 40%, inducible VT, VF were at risk of cardiac mortality.
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| 58P-17 SIGNIFICANCE OF INDUCIBLE VENTRICULAR FLUTTER - FIBRILLATION AFTER MYOCARDIAL INFARCTION B Brembilla-Perrot, C Suty- Selton, A Terrier de la Chaise, P Louis, O Claudon, B Popovic, Nippert, N Sadoul, H Blangy, H Belhakem Cardiology, CHU of Brabois, Vandoeuvre, France The purpose of study was to look for induced ventricular flutter/fibrillation (VF) significance in postmyocardial infarction (MI). Methods: programmed ventricular stimulation (PVS) was performed after MI for syncope (n=232) or systematically (n=840). VF was induced in 291 patients. LVEF, Holter monitoring were collected. Patients were followed 3±1 years. Results: VF was induced 1) in 45 of 232 patients with syncope. 246 of 840 asymptomatic patients, (p < 0.05): 2) 132 of 539 patients with LVEF < 40%, 159 of 533 patients with LVEF > 40% (NS); 3) Cardiac mortality was 37.5% in patients with VF, syncope, LVEF < 40%, 10% in asymptomatic patients, LVEF < 40%, no induc ible arrhythmias (p < 0.01). Cardiac mortality was low in asymptomatic patients (1%), those with syncope (5%), VF, LVEF >40%. VF in patients with LVEF < 40%, syncope predicted cardiac mortality but not sudden death. In conclusion, syncope did not increase VF induction after MI; induced VF increased cardiac mortality in patients with syncope and LVEF < 40%. but not sudden death.
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| 58P-18 CAUSES AND PROGNOSTIC FACTORS OF SYNCOPE IN IDIOPATHIC DILATED CARDIOMYOPATHY B Brembilla-Perrot, C Suty-Selton, A Terrier de la Chaise, P Louis, H Blangy, N Sadoul, E Aliot, O Claudon. Y Al Saleh, Y Juilliere, M Nippert, MD. Cardiology, CHU of Brabois. Vandoeuvre, France The purpose of the study was to know the causes and prognosis of syncope in idiopathic dilated cardiomyopathy (DCM). Methods: Electrophysiological study (EPS), Holter monitoring, tilt test, were performed in 63 patients with DCM (LVEF 27±10%) and syncope. Coronary angiography was normal. Patients were followed during 4±1 years. Results: sustained monomorphic VT was induced in 13 patients (22%), VF in 9 patients (14%), atrial tachyarrhythmia in 17 patients (27%) ; 5 patients (8%) had conduction disturbances; tilt test was positive in 5 patients (8%); syncope was unexplained in 14 patients (22%). Cardiac mortality was 19% in patients with VT/VF and 20% in those without VT/VF. The predictors of cardiac death were a significanly lower LVEF (24±11%) in those who died than in alive patients (29±7) (p < 0.05) and the female sex (50% vs 14%). Presence of nonssustained VT were not predictors of death. In conclusion, various causes for syncope were identified in 78% of patients with DCM, requiring a complete evaluation to indicate a specific treatment. The prognosis depended on sex and LVEF.
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| 58P-19 MODE OF ONSET OF ELECTRICALLY TRIGGERED VF IN TYPE 1 BRUGADA PATIENTS Lerecouvreux M, Carlioz R, Perrier E, Quiniou G, Deroche J, Manen O, Geffroy S The mechanism of ventricular (V) arrhythmias(tachycardia, fibrillation [F]) during programmed V stimulation (PVS) in Brugada patients (P) is not yet elucidated. Purpose of the study: 12 P (12 men, 40+/–10 years old) with Brugada type 1 ECG pattern (coved-type ST elevation with J wave > or equal to 2mm and negative T waves in V1-V3) underwent complete electrophysiology study with PVS. We measured the coupling interval between the last extrastimulus (ES) and the VF (CIVF). Method: PVS was performed in the right V apex with up to 3 premature stimuli at 4 paced cycle lengths (600, 500, 400, 330ms) until the 180ms minimal coupling interval was reached or a sustained VT or VF was induced. When no VT or VF occurred, the same protocol was repeated at the right ventricular outflow tract (RVOT). Results: 2 P had history of syncope, 1 P had familial history of sudden death. Echographic left V ejection fraction was 67+/–5%. Ajmaline testing (50mg IV bolus) induced super-ST-elevation with no arrhythmia in all P. PVS induced 9 VF in 6 P, 5 were induced on a 500ms basic cycle length and 4 on a 400ms basic cycle length, 4 with 2 ES, 5 with 3 ES. Average ES coupling interval responsible for VF was 199ms [180–220]. Average His-V interval was 58ms (+/–17) in P with inducible VF and 50ms (+/–5) in the other ones. The average CIVF was 258ms (+/–14) at the apex and 240ms (+/–8) at the RVOT. All P were free of cardiac event during a 20+/–12 month follow-up. Conclusion: Recent studies suggest that V arrhythmias in Brugada P are initiated by a premature ventricular beat which fires when phase 2 re-entry is made possible by a voltage gradient between epicardial and endocardial cells in the RVOT. Our findings, showing a shorter CIVF at the RVOT, are in accordance with this hypothesis.
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| 58P-20 EFFECTS OF AMIODARONE ON THE P-WAVE WAVELET ANALYSIS IN PATIENTS WITH PAROXYSMAL ATRIAL FIBRILLATION George Dakos, Vassilios Vassilikos, *Ioanna Chouvarda, Haralambos Karvounis, *Nikolaos Maglaveras, Sotirios Mochlas, George Louridas First Cardiology Division, * Laboratory of Medical Informatics, Aristotle University of Thessaloniki, Greece It is known that wavelet transform represents a time scale technique of signal analysis, with the ability to detect transient and small perturbations even when they are hidden in larger amplitudes. Methods: In this study we calculate the energy scalograms of the Morlet wavelet transformed P wave, in two groups of paroxysmal atrial fibrillation (PAF) patients: Group A: 25 patients (12 males, mean age 65 ±7) under amiodarone treatment and Group B: 37 patients (16 males, mean age 61±13) without any antiarrhythmic therapy. Recordings were obtained during sinus rhythm with a 3 - channel digital recorder. Wavelet parameters expressing the mean (MN) and peak (MX) energy of P wave were calculated in the three orthogonal leads (X, Y, Z) and in the vector magnitude (VM), in three frequency bands (200–160 Hz, 150–100 Hz and 90–50 Hz).The P wave duration was also measured in these axes and in the VM. Results: No significant differences were found in gender, age, prevalence of hypertension, atrial size, left ventricular dimensions and function between the two groups. P-wave duration in X, Y axes and in VM was found significantly longer in group A.In the same group of patients MX energy in 150–100 Hz and 90–50 Hz frequency bands in Z-axis were shown to be significant greater. Pduration in Y axis revealed by multivariate analysis as an independent variable of amiodarone treatment.A cut-off value of 100 msec had a sensitivity of 68% and a specificity of 73%. Conclusion:Amiodarone significantly influence the duration and the energy characteristics of P wave in PAF patients.
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| 58P-21 P WAVE MORPHOLOGY IN THE SURFACE ECG DURING PACING FROM THE PULMONARY VEINS AND SUPERIOR VENA CAVA KIMIE OKUBO, ICHIRO WATANABE, YASUO OKUMURA,TOSHIKO NAKAI YUJI KASAMAKI THE SECOND DEPARTMENT OF INTERNAL MEDICINE,NIHON UNIVERSITY SCHOOL OF MEDICINE A significant proportion of focal atrial fibrillation originates in the thoracic veins. Mapping of atrial premature beats is used to identify these premature beats. Methods: All 4 PVs and SVC were paced at 100bpm. 12-leads ECGwas recorded during pacing. P waves were categorized as positive, negative, biphasic or isoelectric. Results: A negative or biphasic P wave in lead I or positive P wave in V1 were helpful in predicting a PV site of origin as opposed to a right atrial site of origin. A positive P wave in II and III distinguished superior from inferior PVs (p<0.01). Negative, isoelectoric or biphasic P waves in leads I and aVL distinguished a left from right PA site of origin (p<0.01). All P wave polarity was similar between RSPV and SVC pacing. But, P wave morphology during RSPV pacing showed notching in 80%, but all P wave morphology during SVC pacing showed monophasic P wave (p<0.001). Conclusions: Analysis of P waves polarity and morphology may be helpful in localizing the PV and SVC that is the origin of a premature depolarization.
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| 58P-22 INDICATIONS AND RESULTS OF RADIOFREQUENCY CATHETER ABLATION OF SUPRAVENTRICULAR TACHYCARDIAS IN CHILDREN Revishvili A.Sh., Baturkin L.Y., Gukasova I.I. Bakoulev Center for Cardiovascular Surgery, RAMS, Moscow, Russia Objectives: Estimation of ability of topical diagnostics of supraventricular tachycardia site in children for determination of indications for radiofrequency ablation (RFA) and for assessment of the efficacy of RFA in children. Methods: In 1999–2003yy electrophysiologic studies (EPS) and RFA were performed in 187 consecutive patients (mean age 9 ±3,6 years) with supraventricular tachycardia (64 pt with WPW, 60 pt with concealed accessory pathway, 10 pt with atriofascicular tract, 16 pt with atrioventricular node reentrant tachycardia (AVNRT), 20 patients with automatic atrial tachycardia and 7 patients with atrial flutter (AFl). Preoperative examination included 12-lead ECG, body surface mapping, Holter monitoring. biochemical markers of myocardial damage were studied before and after EPS and RFA. Results: Success rate of RFA was 94,3% (96,3% - WPW syndrome, 89%-automatic atrial tachycardia, 100%-atriofascicular tract, AVNRT and AFl). Mortality was 0%. One case was complicated by third-degree AV block that required pacemaker implantation. Postoperative recurrence rate was 4,9%. New arrhythmias were detected in 0,8%. All children with recurrences underwent further successful RFA. The most specific and sensitive markers of myocardial damage were troponin T(p<0,05) and troponin I (p<0,05). Conclusion: Preoperative topical diagnostic methods permits localization of the arrhythmia focus and reduces EPS duration and fluoroscopy time. Indications for RFA are determined based on clinical presentation, age, weight, location of arrhythmia site and concomitant pathology. Total duration of RF energy applications should not exceed 5±2 min, at mean temperature 52±3°!.
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| 58P-23 CHARACTERISTICS AND OUTCOME OF LATE ONSET FETAL ATRIAL FLUTTER Abrams DJR, Gardiner HM, Till JA. Department of Paediatric Cardiology, The Royal Brompton Hospital and The Institute of Reproductive and Developmental Biology, Queen Charlotte's and Hammersmith Hospital, London, UK Purpose: To describe the electrophysiological (EP) characteristics, complications and outcome of atrial flutter (AFL) with late gestational onset. Method: 13 cases of neonatal atrial flutter with maternal symptoms and/or documentation of fetal tachyarrhythmia 48 hours pre-delivery were assessed. All had post-natal ECG confirmation of AFL and no hydrops. Results: The median neonatal age was 1 day (range 1–4) with gestational age of 40 weeks (range 35.4–40.7). Typical AFL (counterclockwise) was seen in 10 and reverse typical AFL (clockwise) in 3. Median flutter cycle length (CL) was 153msec (range 136–180). Atrioventricular conduction was 2:1(7), 2:1/3:1 (4) 2:1/3:1 (1) and 3:1/4:1 (1). DC cardioversion (DCC) was successful in 7/8, and pharmacological therapy was successful in 0/4. Flecainide precipitated 1:1 conduction in 2, and there was 1 fatality. Median follow up of 12 survivors is 74 months (range 8–117): all are off medication with no recurrence. Conclusions: AFL may occur late in pregnancy, potentially precipitated by changes in right atrial loading and specific electrophysiological characteristics. DCC remains the treatment of choice and class 1c drugs should not be used.
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| 58P-24 VENTRICULAR FIBRILLATION ASSOCIATED WITH CORONARY SPASM IS TRIGGERED FROM THE PURKINJE SYSTEM JL Pasquié,P Sanders,M Hocini,LF Hsu,Pierre Jaïs, C Scavee, JClémenty,M Haïssaguerre;CHU Bordeaux,France The mechanisms of sudden cardiac death in pts with vasospastic coronary artery disease remains unknown. We report the case of a 52 yo man who had experienced resuscitated sudden death 4 years previously. Evaluation at that time including ergonovin and flecainide testing were negative and he was implanted with an ICD. He presented with 6 episodes of documented ventricular fibrillation (VF) in the 4 months preceding referral. He reported mild chest pain before these episodes with coronary angiogram and ergonovin challenge negative on 2 occasions. While in hospital an episode of VF was documented on 12-lead ECG monitoring. Chest pain was associated with progressive ST elevation in inferior leads followed by the onset of ventricular ectopies (RBBB superior axis; coupling 320msec) initiating short runs of polymorphic VT/VF. Treatment with calcium blocker was ineffective and as such mapping was performed. The ectopy triggering VF was mapped from the left Purkinje (P) system where P potential preceded the onset of QRS by 10msec in sinus rhythm and 25msec during ectopies in the inferior and septal wall of the left ventricle. Repetitive and blocked P activity were noted. Ablation at that site eliminated local P potentials and the clinical ectopy. At 6 months follow-up, 3 episodes of mild chest pain were reported but without any arrhythmic event detected by ICD interrogations. This case demonstrates for the first time in man the role of P arborization in initiating VF in patients with coronary artery spasm.
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| 58-25 TISSUE-SPECIFIC DIFFERENCE PLAYS AN IMPORTANT ROLE IN ACQUIRED LONG QT1 IN ISOLATED RABBIT CARDIAC TISSUES: IMPORTANCE OF BETA-ADRENERGIC RECEPTOR STIMULATION H.R. Lu*, E. Vlaminckx, A. Van De Water, D. Gallacher Center of Excellence for Cardiovascular Safety Research, Johnson Johnson Pharmaceutical Research Development, A Division of Janssen Pharmaceutical N.V. B-2340, Beerse, Belgium Summary: We used a highly selective Iks blocker: (-)-[3R, 4S]-Chromanol 293B [(-) 293B] to mimic LQT1 in 3 difference cardiac tissues in rabbits in vitro. Method and Results: Iks block with (-) 293B at 1 × 10-5 M did not significantly change action potentials in a normal rhythm, bradycardia or tachycardia in all three cardiac tissues. Isoproterenol (Iso:1 × 10-7 M) shortens APD90, and (-) 293 B (1 × 10-5 M) largely reversed this shortening in isolated papillary muscles at 1 Hz (-16% of baseline with iso-group versus -3% with Iso + (-)293B group; p<0.05) and also at 2 Hz (+7% versus -25% with Iso alone; p<0.05), but not significantly in isolated Purkinje fibers. In isolated trabeculae, (-) 293 B in combination with Iso significantly prolonged the APD90 by 15% at 1 Hz (versus -10% with iso-treated group; P<0.05) and by 5% at 2 Hz (versus -11% with Iso-treated alone; p<0.05). Additionally, (-) 293 B (1 × 10-5 M) in combination with Iso (1 × 10-7 M) significantly increased the triangulation of the APD in isolated papillary muscles and trabeculae, but not in isolated Purkinje fibers. Conclusion: Our present study confirms that only during b-adrenoceptor stimulation, pharmacological mimicking LQT1 plays an important role in the APD in isolated ventricular trabeculae and papillary muscles, but not in Purkinje fibers. These results indicate that cardiac tissue-specific differences and b-adrenoceptor activation are both important to the IKs in control of APD in rabbits in vitro.
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| 58P-26 FEVER AND BRUGADA SYNDROME S.OUALI, S. CHABRAK SONIA, N.LARBI, N.KAFSI. A 34 year old male referred to the emergency room for a febrile illness where he experienced two cardiac arrests. He was resuscitated from the two sucessif episodes of ventricular fibrillation and was cardioverted into sinus rythm revealing an electrocardiographic pattern of brugada syndrome (BS). The patient recieved an automatic implantable defibrillator who presented with multiple appropriate discharges because of recurrent episodes of ventricular fibrillation five months latter the implantation. This arrhythmic event disclosed also by an influenza-like febrile illness. Among ten months of follow-up this BS patient display ventricular fibrillation only during febrile illness. The recurrence of ventricular fibrillation in brugada syndrome during febrile state confirms the recent reported cases and the in vitro experimental data that previously established correlation between repolarization and temperature variations in BS patient.
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| 58P-27 ELECTROANATOMICAL MAPPING OF THE RIGHT VENTRICLE IN PATIENTS WITH THE BRUGADA SYNDROME S. Krishnan, MD, D. Kenigsberg, MD, F. Bogun, MD, C. Schuger, MD and R. Brugada, MD. Henry Ford Hospital, Detroit, MI, USA, Masonic Medical Research Laboratory, Utica, NY, USA Background:The right ventricular outflow tract (RVOT) is felt to be the arrhythmogenic region in the Brugada Syndrome. To better understand this substrate, we performed electroanatomical mapping of the right ventricle (RV) in three patients with the Brugada Syndrome. Methods:The Josephson et al. mapping schema was used (sites 13 through 17 are the septal portion of the RV; site 18 [subdivided into zones a, b and c] is the RV free wall). Sites 16, 17 and 18a are the RVOT. Using the CARTO system, 80 electrograms (EGM) were acquired in the first patient, 95 in the second, and 50 in the third. Results:
Comparing the RVOT to the rest of the RV, the bipolar voltages were 1.8±2.5 mv and 4.5±4.5 mv (p<0.0001), respectively, and the unipolar voltages were 5.6±3.4 mv and 8.8±4.0 mv (p<0.0001), respectively. In addition, comparing EGM durations in the RVOT versus the rest of the RV revealed that the bipolar EGM durations were 71±21 ms and 64±22 ms (p=0.07), respectively, and the unipolar durations were 100±30 ms and 99±28 ms (p=0.8), respectively. Conclusion:In our study, in patients with the Brugada Syndrome, the bipolar and unipolar EGMs from the RVOT showed a significantly lower amplitude. When compared to the rest of the RV, the EGMs from the RVOT tended to be broader, as well.
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| 63-1 ATRIAL TACHYARRHYTHMIAS FOLLOWING TRANSCATHETER CLOSURE OF PATENT FORAMEN OVALE ARE RELATIVELY COMMON Jamshid Alaeddini MD, Georges Feghali MD, Stephen Jenkins MD, Stephen Ramee MD, Christopher White MD, Tyrone Collins MD, Freddy Abi-Samra MD, Ochsner Clinic Foundation, New Orleans, Louisiana, USA Purpose: Transcatheter closure of patent foramen ovale (PFO) has recently become more popular. However, the long-term effects of these closure devices on the atrial tachyarrhythmias (ATs) are not known.
Methods and Results: We studied 54 patients (26 (48%) men, age 54±14 year) with a history of cryptogenic stroke and PFO diagnosed by transesophageal echocardiography who underwent transcatheter closure of the PFO by either a 33mm (n=15) or a smaller ( Conclusion: ATs are relatively common following transcatheter closure of PFO. These tachyarrhythmias occur more frequently in patients who receive larger closure devices
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| 63-2 ABLATION OF CRISTA TERMINALIS ATRIAL TACHYCARDIAS WITH NON-CONTACT MAPPING P Insulander, G Kennebäck, F Tabrizi, C Wredlert, M Jensen-Urstad, Dept of Cardiology, Huddinge University Hospital, Stockholm, Sweden Purpose: Right atrial tachycardias (AT) are often crista terminalis (CT) related or dependent. Non-contact mapping (NCM, Ensite) allows mapping foci and to identify slow conduction through critical gaps along CT. Methods: 16 consecutive patients (age 55 (25–75) years, 7 men) with CT related AT were studied with standard electrophysiologic (EP) mapping and with NCM during ablation. Localisation and mechanism (inducible/non-inducible with programmed electrical stimulation) were determined as focal non-inducible, focal inducible or macro re-entry where the critical gaps with slow conduction through CT were mapped. Localisation during EP mapping was compared with NCM. Results: 18 CT related AT were identified in 16 patients (3 focal non-inducible, 7 focal inducible and 8 macro re-entry where a gap in CT was the critical part). 13 AT were successfully ablated, 3 were partially successful (more difficult to induce or non-sustained) and 2 were failures. 5/7 focal inducible AT had an initial region (3–4 cm2) with very slow conduction. All patients with macro re-entry and a gap in CT were successfully ablated. In 5/18 AT standard EP mapping gave an incorrect localisation. Conclusion: Crista terminalis related tachycardias are usually caused by re-entry. Non-contact mapping optimizes analysis and ablation of the arrhythmogenic substrate compared with standard electrophysiologic mapping.
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| 63-3 Comparison of Induced and Spontaneous Atrial Tachyarrhythmias in Patients With a History of Spontaneous Tachyarrhythmias 1Wollmann. C, MD 2, Birnie, D, MD, 2Tang, A, MD 3Boriani, G, MD 4Kühl, M, MS 1Dep. for Cardiology and Angiology, University of Münster, Germany; 2Ottawa Heart Institute, Canada; 3Dep. for Cardiology, University of Bologna, Italy; 4Guidant Induction of atrial tachyarrhythmias (AT/AF) in patients (pts) implanted with an ICD for detection and treatment of atrial and ventricular tachyarrhythmias may be used to optimise ICD programming to enhance the management of spontaneous AT/AF. Methods and results: 89 pts (age 64±13 y, 70% male, CAD in 60% and LVEF 45±16%) with documented paroxysmal AT were implanted with an ICD (PRIZM AW, Guidant) and followed for 6 months. Episodes of induced and spontaneous AT/AF were printed and classified (10 consecutive PP-intervals [CL, ms], measured peak to peak amplitudes [A, mm], separately, a beat-to-beat analysis was performed). 63 pts were induced into AT/AF and were included in this analysis. 51 pts had spontaneous AT/AF, and one representative episode for each of the 34 pts was analysed at the time of the evaluation. Classification of the episodes: An atrial arrhythmia was defined as AF if CL and EGM-amplitudes were unstable, i.e. the isoelectric line indistinguishable. AT's were defined as poly- or monomorphic (mAT, pmAT) if the EGM compared were distinct and the amplitudes similar. Changes from regularity to irregularity were defined as mixed arrhythmias (pm/mAT, pmAT/AF). Induced (63 pts) and spontaneous (34 pts) AT/AF: see table below. 29 pts (85%) had compatible induced and spontaneous episodes and for 5 pts episodes were not compatible.
Conclusions: Our data suggests that the induction of AT/AF may be useful to predict future spontaneous AT/AF in up to 85% of pts. Induction of AT/AF may be helpful to optimize the programming of ICD parameters responsible for detection and treatment of spontaneous AT/AF.
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| 63-4 REENTRANT ATRIAL TACHYCARDIA AS LATE COMPLICATION OF A NEW PV ISOLATION METHOD: LINEAR ABLATION COMBINED WITH POINT BY POINT ABLATION ATTEMPTING EXTENSIVE ISOLATION OF IPSILATERAL PVS M. Goya, Y. Nagata, K. Suzuki, M. Kanemoto, Y. Takahashi, A. Takahashi, H. Fujiwara, Y. Iesaka, Tsuchiura Kyodo Hospital, Tsuchiura, Japan Backgrounds: Electrical isolation of pulmonary veins(PVs) reduced the likelihood of atrial fibrillation(Af). However its result is still unsatisfactory. We developed extensive encircling isolation of ipsilateral PVs(EEIPV) at the junction of left atrium(LA) and ipsilateral PVs using linear ablation at the posterior and point by point ablation at the anterior aspect. Linear ablation had potential risk of macroreentrant atrial tachycardia(AT). We studied its incidence and electrophysiological and clinical characteristics. Methods and Results: We performed 123 EEIPV procedures. In a mean follow-up of 10±5 months, 86% of patients(pts) were free from Af. Eight pts had AT attack(mean cycle length 202 ms) 3.7 months after EEIPV procedure. Three of 8 pts also had Af recurrence. Four pts underwent electroanatomical mapping(EM). In one pt, EM revealed focal activation from the PV and mapping inside the PV showed intra-PV reentry. In 3 pts EM revealed macroreentry. One pt showed figure-8 reentry which was related to the previous ablation line next to the left PVs and two pts showed peri-mitral reentry. Two pts underwent re-ablation targeting AT and three pts targeting recurrent LA-PV conduction. Anti-arrhythmic drugs were prescribed to the remaining 3 pts. All but one pts were free from not only AT but also Af during follow-up period(mean 5.4 months). Conclusions: Linear ablation combined with point by point ablation is effective. It caused considerable number of AT as late complication. The mechanism of AT has some variations and this AT can be controlled by re-ablation or anti-arrhythmic drugs.
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| 63-5 CRYOABLATION OF ATRIAL TACHYCARDIAS WITHIN THE TRIANGLE OF KOCH Klisch A., Stemberg M., Vester E.G., Dept. of Cardiology, Evangelisches Krankenhaus Duesseldorf, Germany Background: Recently cryoenergy catheter ablation has become available with potential advantages compared to radiofrequency (RF) energy. During cryomapping at -30 degrees C a reversible lesion occurs and adhesion ensures the catheter tip remains at the target site for ablation. If the optimal site is obtained cryoablation can be performed by lowering the temperature to -75 degrees C in order to create a permanent lesion. This report describes our experiences with cryoablation of atrial tachycardias (AT) within the triangle of Koch. Methods: 6 patients with inducible ectopic AT within the Koch's triangle were ablated using the CryoCath System (CryoCath Technologies Inc., Canada) with a 9F transvenous catheter (Freezor). After a local electrogram of 40 (30–50) milliseconds preceding the P wave on the surface ECG was obtained cryomapping results in termination of AT. At these sites cryoablation was performed for 4 minutes to create an irreversible lesion. Results: The AT cycle lengths were 380 (330–430) milliseconds and earliest atrial deflection during AT was recorded near the AV junction. AVNRT and AVRT were excluded. After 4 (2–6) cryomaps leading to termination of AT atrial overdrive pacing was performed to monitor AV conduction. Subsequently cryoablation was succesful in all patients using a mean of 3 (2–4) applications. The mean fluoroscopy time was 9,8 (7–12) and the mean duration of procedure was 135 (110–160) minutes. At a 3,8 (2–6) month follow up there were no comlications and no recurrence of AT. Conclusion: Our results demonstrate that cryoablation is safe and effective for ablation of atrial tachycardias. Its application should be considered particularly in patients with tachycardias close to the AV junction to avoid permanent AV block.
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| 63-6 PARAHISIAN ATRIAL TACHYCARDIA: ABLATION IN SINUS RHYTHM USING ELECTROANATOMICAL MAPPING (CARTO®). X.Viñolas, E.Rodriguez, F.Freire, C.Grande, L Azocar, R.Oter, J.Cinca. Cardiology Dpt. Hosp. de Sant Pau.Spain 10% Atrial Tachycardia (AT) are located in the Koch triangle. Ablation in this region has a small but not negligible risk of AV block. Ablation in SR have some advantadges, like better catheter stability. We describe 2 consecutive patients with "parahisian" AT in whom ablation was performed during SR using 3D electroanatomical mapping guidance. P#1: F 62 y, SVT at 150 bpm, 1:1 AV conduction, RP>PR; P (-) in II, III, aVF, V4, V5 y V6; (±) en I, aVL, V1, V2, V3. Sustained AT was induced. Earliest atrial activation was located in right parahisian region (A/V ratio=5 with His deflection= 0,2 mV). 2 RF pulses were delivered during AT (-20ms to P wave) with smallest His deflection <0,2 mV). RF pulses were interrupted due to catheter dislodgement when tachycardia stopped. P#2: female 32 y, cardiac surgery 10 years ago. Recurrent SVT at 130 bpm, 1:1 AV relationship, RP>PR, P(+) DI,aVL, (-) III,aVF, V1,V2,V3, (+/–) II, V4,V5,V6. During EP study only self limited (<1min) AT originating in the high right midseptal region were induced (His <0,1mV). Due to self-limited AT it was not possible to deliver RF current during tachycardia A right atrium Carto® map during AT was obtained in both P. RF pulse was delivered during SR using Carto® map to locate transient effective pulse (P#1) and earliest atrial activation (P#2). During RF pulse, junctional rhythm and transient prolongation of AH interval was observed in both P. Tachycardia was not inducible after the ablation. Conclusion: 3D Carto mapping may help in some cases to perform parahisian AT ablation during SR, specially in cases with catheter instability during AT interruption, allowing better monitorization of junctional rhythm and AV conduction.
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| 64-1 TIME COURSE OF HIGH GRADE PULMONARY VEIN STENOSES AFTER ABLATION OF ATRIAL FIBRILLATION? J. Vogt, J. Heintze, P. Schwartze, H. Buschler, H. Esdorn, A. Peterschröder,, H. Meyer, D. Horstkotte Heart Center North Rhine-Westphalia, Ruhr University of Bochum, Bad Oeynhausen, Germany Pulmonary vein (PV) isolation with radiofrequency ablation (RF) to eliminate triggers is successful in paroxysmal atrial fibrillation. PV stenosis remains the main complication associated with this approach. The onset and time course of progression of PV stenoses are not uniform. In 58 patients (pts) (mean age 58 ± 8 years) with paroxysmal (91%) or persistent (9%) atrial fibrillation refractory to antiarrhythmic therapy who underwent RF PV isolation the anatomy of the 226 PVs was serially characterised by magnetic resonance angiography (MRA) with gadolinium prior to and after the intervention. Results: In 12 PV (5.3%) a high grade stenosis, one with total, one with subtotal occlusion could be found. The mean follow-up of the patients with PV stenosis was 19±3 months (mo). Most often stenoses developed in the left upper PV (8 including one occlusion) after a mean follow-up of 3.6±2 mo. Two PV stenoses in the left lower and two in the right upper PV developed after a mean follow-up of 6 mo. Six stenoses reached their maximal lumen reduction after 6 mo, one stenosis after 9 mo. We found no further progression later than 9 mo. In 17 pts (7% of the target veins) a narrowing below 50% could be demonstrated. The mean time course in 9 left upper, 4 left lower, 3 right upper and one right lower PV was 7.4, 7.75, and 6 mo, respectively. After RF isolation of PV, progression of high grade stenosis and narrowing is mostly terminated after 6, in single cases after 9 mo. In order to detect asymptomatic PV stenoses, MRI or CT scanning is best performed 6 mo and one year after the RF procedure.
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| 64-2 PV DIAMETER REDUCTION AFTER RF ABLATION PREDICTS DEVELOPMENT OF SEVERE STENOSIS Alexander Berkowitsch, Thomas Neumann, Okan Ekinci, Harald Greiss, Thorsten Dill, Klaus Kurzidim, Malte Kunnis, Hans J Schneider, Heinz F Pitschner; Kerckhoff-Clinic, Bad Nauheim, Germany Reduction of initial ostial PV diameter was found in patients directly after radiofrequency PV isolation. The aim of this study was to investigate prognostic significance of the relative reduction of PV diameter (RRPVD) at next day after the procedure for development of severe PV stenosis during long term follow up. Sixty four consecutive patients (mean age/SD = 53/10 years; 24 female) with drug refractory AF were enrolled in the study. PV diameter was evaluated using MR angiography (MRA) one day prior to and one day after the ablation procedure. The further follow up was by MRA every three months after the procedure. Severe PV stenosis was defined as a diameter reduction >70% of the initial ostial PV diameter. RRPVD was analyzed as dichotomized variable using cutoff determined by the method of maximizing the log-rank test statistics. A total of 228 PV was treated in study patients. The mean RRPVD was 8% with SD=14%. Severe stenosis was found in 13 PV within follow up (mean/SD=6.5/4.6 months). The optimal cutoff point was found at RRPVD=25%. The Kaplan-Meier analysis confirmed strong association of RRPVD>= 25% with long term development of PV stenosis (p<.0001; Sensitivity = 42%; Specificity = 90%). After adjustment of RF ablation parameters RRPVD was tested in multivariate Cox regression model, which revealed RRPVD to be strongest predictor for development of severe PV stenosis (p<.0001; HR= 4.97). In conclusion, RRPVD >= 25%, observed by MRA at the next day after the procedure is a strong independent predictor for development of severe PV stenosis.
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| 64-3 ASSESSMENT OF PULMONARY VEIN STENOSIS/NARROWING BY MULTI-SLICE COMPUTED TOMOGRAPHY AFTER PULMONARY VEIN ABLATION: COMPARISON BETWEEN EXTENSIVE ENCIRCLING ISOLATION OF IPSILATERAL PULMONARY VEINS AND INDIVIDUAL PULMONARY VEIN ISOLATION Ken Kurihara, Atushi Takahashi, Yasuteru Yamauchi, Koji Kumagai, Yasuhiro Yokoyama, Akira Satoh, Yasuaki Tanaka, Kenzou Hiraoka, Mituaki Isobe, Kazutaka Aonuma, Cardiovascular Center, Yokosuka Kyosai General Hospital, Kanagawa, Japan Pulmonary vein (PV) stenosis has emerged as a serious complication after individual PV isolation (I) in patients with atrial fibriilation (AF). The aim of this study was to evaluate the incidence of PV stenosis/narrowing after extensive encircling isolation of ipsilateral PVs compared to those after individual PVI. Methods: Consecutive 37 patients with drug-refractory AF underwent individual PV ablation (group A; n=17) and extensive encircling ablation of ipsilateral PVs (group B; n=20). 3D Multi-slice computed tomography (MSCT) was performed to measure the PV ostial dimension before and 3 months after ablation. Results: PVI was successfully achieved in 57 PVs of group A and all 80 PVs in group B. With MSCT performed after ablation, 16 PVs from 9 group A patients and 8 PVs from 5 group B patients had 22±14% (7–50%) and 14±6% (7-22%) narrowing of PV ostia, respectively (p<0.05). Narrowing >= 25% was observed in 4 PVs (1 left superior PV, 2 left inferior PVs and 1 right superior PV) from 4 group A patients including 1 patient with 50% stenosis at the left superior PV, whereas there were no narrowing>25% in group B patients (p<0.05). Conclusions; Extensive PV ablation of ipsilateral PVs appears to be superior because of the reduction of significant PV stenosis/narrowing.
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| 64-4 REDUCTION IN PULMONARY VEIN DIAMETER AFTER RADIOFREQUENCY CATHETER ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: A CONTRAST-ENHANCED THREE-DIMENSIONAL MAGNETIC RESONANCE IMAGING STUDY Anselme F, Savouré A, Gerbaud E, Gahide G, Cribier A, Dacher JN. Pulmonary veins (PV) stenosis have been reported as a complication of focal atrial fibrillation (AF) RF ablation. The aim of our study was to prospectively evaluate incidence and degree of PV stenosis after AF ablation, using contrast-enhanced 3D magnetic resonance imaging (MRI).
Methods: PV segmental electrical disconnection was performed in 24 consecutive patients (pts, mean age of 52±10 y) with the help of Halo catheter, and using 4 mm irrigated tip RF catheter. Maximal power delivery was set at Results: Mean PV ostia diameters were 20±4, 18±4, 19±4, 17±3 and 19±4, 17±4, 18±4, 15±3 mm for right superior, right inferior, left superior and left inferior PV before and after ablation respectively (p<0.05). PV narrowing between 10–20%, 20–30% and 30–40% was documented in 22%, 12%, 3% of the PVs and in 62%, 50%, 12% of the pts respectively. No PV occlusion nor PV stenosis > 40% was observed. At this short term follow-up, there was no significant modification of the left atrial dimensions. Conclusion: Systematic evaluation of PV diameter before and after AF ablation using 3D MRI technique allows identification of slight but significant PV narrowing in more than half of the pts.
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| 64-5 PULMONARY HEMODYNAMICS AT REST AND DURING EXERCISE IN PATIENTS WITH SIGNIFICANT PULMONARY VEIN STENOSIS AFTER RADIOFREQUENCY CATHETER ABLATION FOR DRUG RESISTANT ATRIAL FIBRILLATION T. Arentz, T. Blum, J. von Rosenthal, G. Bükle, R. Weber, L. Haegeli, J. Stockinger, D. Kalusche Herz-Zentrum, Bad Krozingen, Germany PURPOSE: Iatrogenic pulmonary vein (PV) stenosis after radiofrequency catheter ablation (RFA) for atrial fibrillation is a new problem in cardiology. The effects of stenosis on the pulmonary circulation during long term follow up are not known. METHODS: We performed MRI and Swan Ganz (SG) right heart catheterisation at rest and during exercise 49±14 months after RFA in patients with known PV stenosis (>70%) or occlusion. RESULTS: 12 patients (58±7 years) were studied, only 3 patients had dyspnea during vigorous exercise, none of these underwent previous PV angioplasty. MRI results: ostial PV occlusion N=5, 7gt;70% ostial stenosis N=7, >70% distal stenosis of the main vessel N=3. SG results: At rest no patient had pulmonary hypertension compared to an age matched group. At 50 W, 3 patients and at 100 W 3 patients had elevated PC (pulmonary capillary) and PA (pulmonal artery) pressure with normal CI (cardiac index). All 3 patients with stenosis/occlusions of 2 PV were affected. Three patients stopped exercise due to dyspnea, 2 due to muscular exertion. CONCLUSIONS: One or 2 significant PV stenosis/occlusions do not create pulmonary hypertension at rest. However, during exercise 50% of these patients had pulmonary hypertension with normal CI. All these patients need to be followed for the risk of progression of pulmonary hypertension.
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| 66-1 NATURAL COURSE OF ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA-CARDIOMYOPATHY - REGISTRY WITH 313 PATIENTS. Peters Stefan - Cardiology, Quedlinburg, Germany For several years attempts are made to provide data to the natural course of arrhythmogenic right ventricular dysplasia_cardiomyopathy (ARVD/C). In a multicentric registry since 1988 including 313 patients the diagnosis of ARVD/C was made according to ISFC/ESC criteria and a follow-up was performed by questionaires and telephone interviews. Data about mortality, sudden cardiac death (SCD), syncopes, heart failure and risk factors of SCD should be obtained. Results: Overall mortality was 2.9% (n=9) due to SCD in 1.6% (n=5), heart failure in 1% (n=3) and postoperative death after heart transplant in 0.3% (n=1). Risk factors of SCD were LV dysfunction in 4 cases (80%), syncopes in 5 cases (100%) and positive family history in one case (20%). In three other families SCD without definite diagnosis occurred, further events did not happen. Risk factors of aborted SCD in 21 patients (7%) were LV dysfunction (43%) and syncopes (38%). 77 patients (25%) suffered from non-documented palpitations, 70 patients were completely asymptomatic from arrhythmic events (22%). Atypical chest pain was present in 132 cases (42%). Syncopes occurred in 45 cases (14%) due to VT's in 19 cases (42%), AV block in 6 cases (13%) and unexplained mechanisms in 20 cases (44%). Symptoms of heart failure were present in 12 cases (3.8%). Conclusions: ARVD/C is characterised clinically by multiple findings with an overall good prognosis. Risk factors of SCD are individually different, a family history plays a less important role than in other forms of cardiomyopathy.
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| 66-2 QUANTITATIVE ANALYSIS OF SIGNAL-AVERAGED ELECTROCARDIOGRAM IN PATIENTS WITH BUNDLE BRANCH BLOCK: EVALUATION IN ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY Kanki Inoue, Katsuya Kajimoto, Nobuhisa Hagiwara, Jun Umemura, Hiroshi Kasanuki It is difficult to distinguish between idiopathic right ventricular tachycardia (Idiopathic RVT; IRVT) and arrhythmogenic right ventricular cardiomyopathy (ARVC). In order to differentiate patients with IRVT and ARVC by signal-averaged electrocardiogram (SAECG) despite bundle branch block (BBB), we evaluated the two SAECG parameters quantitatively: root mean square voltage for the last 40ms (RMS40) and a ratio of the duration of low amplitude signalmv to total filtered QRS duration (LAS40/f-QRS ratio). Methods: 84 patients with RVT (IRVT=33pts, ARVC=51pts) were investigated by SAECG. In 42 patients without BBB and 42 patients with BBB, the values of the two variables (RMS40 and LAS40/f-QRS ratio) were analyzed. Then, we retrospectively investigated the efficacy of new combination criteria (RMS40mV and LAS40/f_QRS ratio>0.34) for differentiating patients with IRVT and ARVC by SAECG despite BBB.Results: 1) In 42 patients with BBB, the combination criteria of RMS40mV and LAS40/f-QRS ratio>>0.34 distinguished the ARVC patients with a specificity of 80%, a positive predictive value (PPV) of 94%, and a negative predictive value (NPV) of 80%. 2) In all 84 patients, this criterion distinguished the ARVC patients with a sensitivity of 92%, a specificity of 82%, a PPV of 89%, and a NPV of 87%. Conclusion: This criteria showed effective for identifying ARVC patients among RVT despite BBB. Therefore, a diagnosis of ARVC can be made reliably on the basis of clinical presentation, imaging techniques, and this quantitative analysis of SAECG.
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| 66-3 VALUE OF SIGNAL AVERAGED ECG AND PROGRAMMED VENTRICULAR STIMULATION IN ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA/CARDIOMYOPATHY Pezawas T, Kastner J, Stix G, Wolzt M, Schmidinger H, University of Vienna, Department of Cardiology, Austria Introduction: Not all patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are at risk for sudden cardiac death. The purpose of this study was to test the arrhythmia predictive values of programmed ventricular stimulation (PVS) and signal averaged ECG (SAECG). Methods and Results: PVS was performed in 30 ARVD/C patients: 21 patients had sustained monomorphic VT (smVT) (TCL=289±53 msec), 5 non-smVT (TCL=333±89 msec), 3 ventricular fibrillation and 1 presented with syncope only. On PVS 16 out of 21 patients with smVT (76%) were inducible in smVT. Fast smVT (232±24 msec) was induced in 10 patients. An ICD was implanted in these 10 patients, in 3 patients with ventricular fibrillation and in one patient with documented fast non-smVT (194 msec) (ICD group, n=14). Slow smVT (335±39msec) was induced in 6 patients. The non-ICD group (n=16) consisted of these 6 (after serial drug testing) finally non-inducible patients and the remaining 10 non-inducible patients, respectively. Late potentials with SAECG were detected in 10 ICD and in 3 non-ICD patients, respectively. During 6.3±3.2 years 10 ICD patients received appropriate therapies and only one non-ICD patient experienced slow smVT (324 msec). There were 4 non sudden-cardiac deaths in both groups. The positive and negative predictive values, the sensitivity and specificity of PVS and SAECG for fast VT or sudden cardiac death ranged between 82 and 95%. Conclusion: This study demonstrates for the first time that SAECG and PVS reliably detect ARVD/C patients who are at risk for sudden cardiac death. ICDs are the treatment of choice in patients with fast smVT. Slow smVT justify drug treatment or VT ablation.
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| 66-4 DEMOGRAPHIC AND CLINICAL DATA ISSUED OF THE FRENCH BRUGADA SYNDROME REGISTRY (COBRA) Lerecouvreux M, Le Marec H, Leenhardt A, Clémenty J, Frank R, Blanc JJ, Mabo Ph, Gras D, Le Heuzey JY, Carlioz R There is few information about demographic and clinical data concerning Brugada Syndrome (BS) patients (P) recruited from multicenter national study. 19 foremost arrhythmias centers in France were contacted to include BS cases in a national registry (COBRA: BrugadA syndrome Collective Observatory). For each BS P were collected familial history (FH), presence of symptoms (S) or not, arrhythmic events, basal ECG and/or after Na channel blockade (NCB), EP testing results and therapeutic options at the time of diagnosis. From 01/02 to 12/03, 297 P (male 76%), [mean age 44(6–83) years] were included. 112 (38%) had S: syncope 56 (19%), dizziness 39 (14%), palpitations 41 (14%), aborted sudden death (SD) 13 (5%), documented spontaneous ventricular (V) 21 (7%) or atrial 25 (8%) arrhythmias, or others S 40 (13%). 193 (35%) had FH of SD, 84 (28%) FH of BS. Out of 247 ECG reviewed by the COBRA committee, according to the European task force ECG criteria (coved or saddle back type ST elevation >= 2mm, T wave flat or negative in V1-V3), 117 (47%) were classified as type 1, 53 (22%) as type 2. 132 (53%) P with atypical ECG underwent NCB resulting in 108 (82%) type 1 conversion. Programmed V stimulation was positive (sustained V tachycardia or fibrillation) in 105/246 (43%). ICD were implanted in 118 (40%). Genetic analysis for 150/297 (SCN5A coding region) are in progress. Conclusion: 297 P were included in the COBRA registry; a large majority satisfied to the BS ECG criteria; near 60% had personnal or familial history of SD or BS, 50% had spontaneous or triggered VA. Follow-up and recorded events will be essential for appropriate risk stratification.
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| 66-5 C-REACTIVE PROTEIN AND ACUTE VENTRICULAR TACHYCARDIA IN ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY/ DYSPLASIA Hopital de la Salpêtrière Paris The role of inflammation in the physiopathogeny of atrial fibrillation has been demonstrated. We have tested the hypothesis of an increase in C-Reactive Protein (CRP) blood level in Arrhythmogenic Right Ventricular Dysplasia (ARVD) with recent episodes of ventricular tachycardia (VT). Methods: From January 2001 to February 2003, we prospectively studies 25 ascertained ARVD patients referred with VTs or infundibular premature beats. Exclusion criteria were recent infectious disease (< 1 month) and ischemic heart disease. Cardiac tests included ECG, holter monitoring, SAECG, coronary angiography, left and right ventricular angiography. CRP was tested in all patients on admission. Two different methods were used to analyse the serum level of CRP: immunobidimetric integra 400 Roche (18/25 patients) and turbidimetric petina/bade Behring(7/25 patients). Finally, 19 patients were retained. Results: 5 patients had elevated CRP (CRP+), 7 had recent documented VT (VT+), 5 had CRP+ and VT+, 2 had CRP- and VT+, 0 had CRP+ and VT- Fisher's exact test was used to analyse the link between CRP and recent VT (p= 0.005; Phi coefficient = 0.764). Kruskall–Wallis test was used to analyse the influence of delay between VT and CRP test and right ventricular changes in angiography (p= 0.724). We found a correlation between CRP elevation and recent VT, but the sequence of events is still to be specified. No influence of degree of dysplasia was found. Conclusion: Inflammation suggested by the rise of CRP, plays an important role in the induction of ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy/dysplasia.
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| 66-6 LONG TERM SURVIVAL OF 229 ARVC/D PATIENTS-A TIERTIARY RETROSPECTIVE STUDY Fontaine G Lacotte J Hidden-Lucet F Himbert C Frank R Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVD) is entailed by the risk of sudden cardiac death and heart failure. Objective: The aim of this study was to evaluate the long term outcome of a cohort of 229 ARVD patients. Method: The starting point of the study was birth, the end point was the last information obtained by consultation or direct phone call. Special attention was paid to classify the end point of the study for each patient. Complete cases are patients with death, heart transplant, tachyarrhythmias recorded from defibrillator's memory or resuscitated from cardiac arrest (group A). Also complete case are patients with hemodynamic cardiac failure uncontrolled by common drug therapies (group B). Kaplan-Meier curves were used to study survival. Results: The study population included 173 male (75%) age 44±16 (9–88). Four patients had a non cardiac death. The series consisted of 13 patients in group A and 14 in group B. No patient reached the end point of the study before age 42 in group B. A continuous attrition rate from age 42 to the end of the study at age 88 was observed (2%/year). In group A the attrition rate was similar 1–2%/year but occurred 15 years earlier. No patient had a major event before age 19. The remaining cases showed a clustering in two subgroups. In subgroup I, 9 patients reached the end point in age 19–40, in subgroup II 4 patients clustered in age 58–70 p<0.001. The reason for this unexpected clustering is unknown and needs to be confirmed by a larger international study. No major arrhythmic event was observed after age 70. Conclusion: Attrition rate of ARVC/D are similar (1–2%/year) but occurs 15 years later by CHF as compared to arrhythmic events. In this group two clusters are identified at age 20–40 and 50–70.
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| 69-1 10-YEARS EXPERIENCE WITH CAPSURE EPI BIPOLAR EPICARDIAL PACING LEAD IN CHILDREN Robert M. Hamilton, Christine Chiu. The Hospital for Sick Children,Toronto, Canada Background: Epicardial pacing remains important for pediatric patients, however, previous epicardial leads have shown poor performance with frequent problems of high thresholds and lead fractures. Objective:We report our single center long-term experience with a bipolar steroid eluting epicardial pacing lead. Methods:Retrospective chart review was conducted on consecutive 10366/4968 leads implanted and in use with a pacing system: Pacing threshold, sensing and impedance measurements as well as any lead related complications were obtained. Kaplan-Meier survival analysis is performed using SAS. Results: 85 atrial (A) and 163 ventricular (V) leads were studied showing 72% and 63% survival at 9 years respectively. Chronic median thresholds at 6 years: A pacing 1.10 uJ (0.35–9.96 uJ) and V pacing 1.51uJ (0.21–7.76 uJ); A sensing 2.88mV (0.6–11.20mV) and V sensing 7.0 mV (2.4–38.1mV); average impedances at 6 years: A 745W + 150W V 757W + 119W. Lead related complications were high threshold (1A, 22V), Sensing problems (3A, 2V), Lead fracture (1A, 9V), Lead insulation problem (4V), electrode dislodgement (2V) and combined threshold and sensing problem (3A). Conclusions:This new epicardial pacing lead showed clinically acceptable performance and showed improvements over previous types of epicardial pacing leads.
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| 69-2 LONG-TERM PERFORMANCE AND SURVIVAL OF A STEROID-ELUTING BIPOLAR EPICARDIAL PACING LEAD IN CHILDREN Urs Bauersfeld, MD, Mariette Rahn, MD, Rene Prêtre, MD, Leo Kretzers, Msc. University Children's Hospital Zurich, Switzerland, and Bakken Research Center, Maastrichy, The Netherlands Background: Cardiovascular anatomy or small patient size may necessitate the insertion of epicardial pacing leads. The aim of the study is to analyze long-term survival, impedance and threshold changes of bipolar steroid-eluting epicardial pacing leads in children. Methods: In 56 children 95 (29 atrial, 56 ventricular)Medtronic CapSure Epi 10366 or 4968 pacing leads were implanted. The Medtronic CapSure Epi 4968 lead has platinized, porous electrode surfaces that are coated with dexamethason sodium phosphate. Threshold values and measured data were obtained at 6 months intervals. For statistical regression analyses threshold data were adjusted by the formula E = 1000 × Voltage2 × pulse width/impedance. Congenital heart disease, surgical access and lead position were analyzed as potential risk factors for poorer lead survical and lead performance. Results: During 3.2 years follow-up atrial and ventricular leads demonstrated no significant changes over time in impedance, energy and sensing thresholds. Subanalyses revealed significantly better ventricular sensing after surgical access by left thoracotomy (LV lead). There were 3 atrial (1 fracture) and 7 ventricular (3 fractures) lead failures Conclusion: Long-term follow-up data demonstrate high survival rates ({small tilde} 85% at 5 years) for bipolar steroid-eluting epicardial pacing leads. Significantly better ventricular sensing is obtained with left ventricular leads. Low pacing thresholds and stable sensing thresholds and impedance are achieved. Thus, reliable long-term pacing can be assured with these leads.
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| 69-3 LONG-TERM RESULTS OF EPICARDIAL STEROID ELUTING LEAD IMPLANTATION FOR PERMANENT CARDIAC PACING USING MINIMALLY INVASIVE TECHNIQUE Revishvili A.Sh., Serguladze S. Y., Shmul A.V. Bakoulev Center for Cardiovascular Surgery, RAMS, Moscow, Russia In 1997–2003yy. we have performed 25 operations (14 men, 11 women, mean age 12.8 ± 9.8) using videothoracoscopy techtoque for implantation of myocardial leads in 2 patients and minimally invasive surgery for bradyarrhythmias in 23 patients. Videothoracoscopy techtoque employing three ports (one 5-mm and two 12-mm) were used for implantation of myocardial leads in two infants with thitd-degree AV block. Permanent VVIR pacemaker was implanted in abdominal position. In 14 children with third-degree AV block (mean weight 11.2 ± 4.2 kg) unipolar or bipolar steroid eluting epicardial leads were implanted through right lateral 3–4cm minithoracotomy, using videomonitoring system VISTA 8000. Permanent VVIR or DDDR pacemaker was implanted in abdominal position. In early postoperative period the stimulation threshold was 0.8 ± 0.3 V in atria and 0.7 ± 0.4 V in ventricles. The A-wave amplitude was 8.2 ± 3.5 mV and R-wave amplitude was 12.5 ± 2.5 mV. During the 6 years of follow-up there were no significant changes of these parameters (p=0.1) Conclusion. Implantation of steroid eluting epicardial leads for permanent pacing using videothoracoscopy techtoque and lateral minithoracotomy is a safe and effective approach for treatment of children with third-degree AV block. In addition, it obviates the need for radiation exposure and gives good cosmetic results.
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| 69-4 ANTIQUE HOOK LEAD FOR EPICARDIAL LEFT VENTRICULAR RESYNCHRONISATION Nicolas Bonnet, S Varnous, P Leprince, V Bors, A Pavie, I Gandjbakhch La Pitié-Salpêtrière hospital, Paris, France Left ventricular (LV) epicardial approach is an alternative for ventricular resynchronisation but there is few choice of epicardial leads and it is a compromise between implantability and thresholds. We analyze ours results using an ancient epicardial lead for LV resynchornisation. From oct-02 to dec-03, 37 patients (22 men, mean age 64) were implanted with the 4951M (Medtronic) lead on the LV through a minithoracotomy for ventricular resynchronisation. 5 patients were redux for sternotomy. There was 28 dilated and 9 ischemic cardiomyopathies. One lead was used in 2 patients and 2 leads were used in 35 with connection to a y for bipolar pacing. This lead is intramyocardial, hook designed, without steroid, with an IS-1 connector. Results: the lead placement was possible in all patients with an acute threshold of 0.89 ± 0.66 V and an impedance of 462 ohm. The epicardial site was lateral and basal in all patients. Duration of intervention for LV lead placement was 25 minute ± 14. There was no morbity imputable to lead itself. The postoperative course was simple in 96%. The threshold at 1 and 3 monthes was 1.7 ± 0.9 V and 1.8 ± 1.2 V. It was worse than thresholds of lead with steroid elution. There was no lead dislodgment, no lead fracture and no infection. The ancient 4951 M (Medtronic) hook designed epicardial lead is easy, fast and safe to implant on the LV for cardiac resynchroniation through a minithoracotomy. Improvement of electrical quality of the epicardial lead is crucial in the near futur.
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| 69-5 Effectiveness of Transvenous and Epicardial Left Ventricular Leads. S. Galvao Filho1, S. Gandra2, J.C. Pachon3. R. Zarza4, W.-P. Wolf5. 1Beneficencia Portuguese de Sao Paulo, Brazil; 2Santa Casa de Sao Paulo, Brazil; 3instituto Dante Pazzanesse de Cardiologia Sao Paulo, Brazil; 4Biotronik Brazil; 5Biotronik Erlangen, Germany Introduction: For cardiac resynchronization therapy (CRT) the left ventricle (LV) can be stimulated by use of transvenous or epicardial leads. We evaluated the effectiveness of coronary sinus vs. epicardial LV leads regarding their electrical performance. Methods: 13 heart failure patients (59 ± 15 years, 10 male. NYHA class 3,1 ± 0.5, QRS width 148 ± 25 ms, 11 with non-ischemic etiology, 6 with Chagas disease) were implanted with a CRT pacemaker Stratos LV (Biotronik, Germany). Biventricular stimulation was realized in Group I (n=6) through coronary sinus leads (Corox LV-H, Biotronik) and In Group II (n=7) through epicardial leads (ELC 54 UP, Biotronik). Pacing threshold (at 0.5 ms) and impedance (at 4 V and 0.5 ms) were determined at implantation, discharge, 1, 2, 3 and 6 months post-operatively. All measurements were performed in unipolar configuration. Results: Development of pacing threshold (table) did not differ significantly between the two groups. The trend of impedance revealed significant differences between the lead types investigated. Whereas impedance of the epicardial leads decreased and remained at a low level, the values for Corox LV-H first decreased and subsequently increased again. In the long term mean impedance was approx. 110% higher with Corox LV-H.
Conclusion: Compared with tranvenous LV leads, the use of epicardial leads reduces the lifetime of CRT devices by 8–15%. This may be of clinical relevance for about 15% of all CHF patients with a CRT indication. Future development of epicardial leads should focus on ensuring high impedance.
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| 69-6 ENDOSCOPIC EXTRAPLEURAL IMPLANTATION OF PACEMAKER ELECTRODES S.N.Lukashov, G.N.Ursol, E.V.Kolesov National University, Dnepropetrovsk, Ukraine Objective. We have developed endoscopic subxyphoidal extrapteural approach for straight implantation of pacemaker electrodes. Methods and material. For electrode delivery 2 cm bore rigid endoscope was used. Due to availability all electrodes were of screw-in type. The approach was used in more than 1000 patients for AAI, VVI, VAT and DDD stimulation. Mean age of patients was 66,4 years. In 97% of patients detection and stimulation thresholds remained stable in follow up period up 15 years. In 3% of patients of learning cohort exit-block occurred due to oblique screwing of the electrode spiral. Bidirectional visual control of the electrode position as well as ways of delivery and fixation of electrodes to left ventricle wall are now under experimental investigation. Conclusion. Straight endoscopic ECS could be a reliable alternative for analogous transvenous methods.
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| 73-1 A NOVEL INSPIRATORY IMPEDANCE THRESHOLD DEVICE MAY DIMINISH ORTHOSTATIC INTOLERANCE Daniel P. Melby, MD, Fei Lu, MD, PhD, and David G. Benditt, MD. U of MN, Minneapolis, MN Background: Orthostatic intolerance (OI) is an important clinical problem with few treatment options. To evaluate a new therapeutic approach, the potential benefit of an inspiratory Impedance Threshold Device (ITD) for reducing posturally-induced BP fall was examined in healthy subjects. The ITD offers moderate resistance to inspiration, forcing development of greater negative intra-thoracic pressure and enhancing venous return to the heart. Methods: Subjects were randomized to either an active or placebo ITD. BP, HR, and stroke volume (SV) were recorded using a Portapress monitor. Continuous monitoring was performed as each subject breathed through the ITD for 30 s while lying supine, and then for an additional 30 s after standing upright. One hour later, the test was repeated with the alternate ITD (i.e., active or placebo) to that used first. Hemodynamic benefit was defined as a reduction of <20% in maximum standing-induced BP fall with active vs. placebo ITD. Symptoms were assessed using a 10-point scale: 0 (None) to 10 (Severe). Data are presented as % change from baseline (Students paired t test). Results: Nineteen healthy subjects (12 females) aged 18 to 56 years (mean 37.6 years) were enrolled. ITD reduced postural BP fall in 8 subjects (responders, 42%), and had no hemodynamic benefit in 11. Comparing active to placebo ITD in responders, the maximum drop in SBP, DBP, and SV at 30 s after standing was 11% vs 29% (p=0.02), 18% vs 39% (p=0.01), 21% vs 26% (p=0.30). Maximal rise in HR was 31% vs 35% (p=0.34, active vs placebo). Symptom status was similar in active or placebo tests, suggesting no adverse ITD effect. Conclusion: The ITD is a novel treatment that, with further study, may prove beneficial in certain individuals with OI.
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| 73-2 BLOOD PRESSURE RESPONSE TO SUPINE TO STANDING TRANSITION USING AN ORTHOSTATIC COMPENSATION ALGORITHM Hung-Fat Tse, Chung-Wah Siu, Vella Tsang, Euljoon Park,* Gene A. Bornzin,* Cannas Yu,* Michael Benser,* Chuk-Pak Lau, Cardiology Division, Department of Medicine, University of Hong Kong; *St Jude Medical, Sylmar, USA. Introduction: Upon standing from a supine position, the normal response is an increase in heart rate to maintain blood pressure (BP). Patients with chronotrophic incompetence might fail to increase their heart rate upon standing and experience orthostatic hypotension. We evaluated a new algorithm that uses an accelerometer signal to detect sudden activity following a prolonged rest to trigger a two minutes increase in pacing rate to 94 ppm. Method: Ten patients underwent a control study in which cuff BP was measured before standing and 0.5, 1, 1.5, 2, 3 minutes after standing at their programmed base rate. The study was repeated using the new algorithm to increase rate upon standing. Results: Five patients that displayed a 20 mmHg drop in systolic BP upon standing were deemed as orthostatically incompetent (OI). The remaining five patients were regarded as normal. Average BP was defined as 1/3 systolic BP + 2/3 diastolic BP. OI patients displayed significant increase in their average BP upon standing with the algorithm over control (1 min: 3.4 vs -10.3 mmHg; 1.5 mins:7.0 vs. -4.9 mmHg; 2 mins: 1.6 vs. -6.7 mmHg; 3 mins: 2.5 vs. -8.5 mmHg, all p<0.05). Conclusion: The preliminary results of this study suggest that the orthostatic compensation algorithm maintains BP upon changes in posture in patients that were orthostatically incompetent.
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| 73-3 USE OF TILT TRAINING IN THE MANAGEMENT OF PATIENTS WITH VASOVAGAL SYNCOPE Osnat Gurevitz, David Bar-Lev, Eyal Zimlichman, Gail Rosenfeld, Michal Benderly, David Luria, Yitzhak Kreiss, Michael Eldar, Michael Glikson Background: Syncope is one of the most common conditions in young adults. Previous non-randomized trials have shown effectiveness of tilt training in preventing vasovagal syncope. This prospective, randomized study was undertaken to evaluate the role of tilt-training in young patients with vaso-vagal syncope. Methods: Patients aged 18–19 years (N = 33, 22 male), with a clinical diagnosis of vasovagal syncope and a positive tilt test were randomized, after signing informed consent, to either 3 months of daily tilt training (group 1), or no training (group 2). Patients were excluded if any cause for syncope other than vaso-vagal was suspected according to careful clinical evaluation. Patients in both groups were instructed to increase liquid and salt intake, and to refrain from syncope-inducing situations Results: There was no difference in baseline clinical parameters such as age, gender, age at first syncope, number of episodes, and the time to syncope during initial tilt testing between groups. Overall compliance to lifestyle modification measures was 82%, and similar between groups. Compliance to tilt training was 87% during the first month, and declined to 53% over the next 2 months. Over the first 6 months post randomization 11 group 1 patients and 7 group 2 patients experienced syncope. The average number of syncope spells per patient over the 6 months before randomization was 2 in both groups. Over the first 6 months post-randomization the average burden of syncope was 1.9 events per patient in group 1, versus 0.25 in group 2. Conclusions: Daily 3 months tilt training was not superior to lifestyle modification alone in preventing vasovagal syncope in young patients.
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| 73-4 ASSESSMENT OF ORTHOSTATIC SELF-TRAINING IN NEUROCARDIOGENIC SYNCOPE Haruhiko Abe, Yasuhide Nakashima 2nd Dept. of Intern. Med. University of Occupational and Environmental Health, Kitakyushu, Japan We assessed the efficacy of daily sessions of home orthostatic self-training (30 minutes per session standing against the wall without moving) for the prevention of neurocardiogenic syncope in 37 patients. Of these patients, 10 were instructed to train two sessions per day, 14 were instructed to train one session per day, and the remaining 13 were instructed to train one session every other day. The patients who conducted one to two sessions of training per day continued to do so over a 6-month follow-up period, during which time none of them experienced spontaneous syncope. Only 5 of 13 patients who were requested to train once every two days were able to continue doing so over the complete 6-month follow-up period; however, no spontaneous syncope was observed in these 5 patients. The remaining 8 of 13 patients could not continue their home training, and syncope or presyncope reoccurred in 3 of them during the follow-up period. We concluded that one session per day of home orthostatic self-training is recommended for the prevention of neurocardiogenic syncope.
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| 73-5 A NEW TREATMENT OF NEUROCARDIOGENIC SYNCOPE(NCS) AND/OR FUNCTIONAL AV BLOCK(FAVB) WITH RF-ABLATION Pachon JC;Pachon EI;Pachon J;Lobo TJ;Pachon MZC; Albornoz RN;Jatene AD - Sao Paulo Heart Hospital and Cardiology Institute Background:The NCS is the most frequent syncope in young patients(p). The cardio-inhibitory form presents sinus bradycardia and/or arrest but may have intermittent FAVB. The treatment (drugs/pacemakers) may present poor results. Purpose: Our goal is to use the RF-ablation to eliminate cardiac parasympathetic ganglia in order to change the autonomic drive enabling the NCS/FAVB cure without pacemaker. Methods: 6 p without apparent cardiopathy were treated, ages 29±9yrs, having NCS with predominant or isolated FAVB(3), dizziness(6) and/or syncope(4). They were submitted to echocardiogram, Holter, stress-test, tilt-test, electrophysiologic study and thermo-controlled RF-ablation in the AV(6) and in the sinus(2) node neighborhood. The procedures were control led by mapping the AV and the sinus node by the right-Fourier-shifting, by thermal response, by increasing the Wenckebach point(WP), by decreasing the sinus cycle length and by reducing vagus-maneuver response. Results: The WP was increased(121.3±14 to 160.3±9ppm)*, the sinus cycle length was decreased(954±136 to 826±80ms)* and the AV refractoriness was decreased(385±52 to 335±30ms)* [p<0.05]. All the p are asymptomatic without drugs(FU=5.7±4m). The Holter control showed normal AV conduction and confirmed disappearance of the intermittent FAVB. The Tilt-test control was normal. Conclusions: 1.The controlled RF-ablation in the neighborhood of the sinus and AV nodes may cure the cardio-inhibitory NCS and the functional AV block; 2.The possible mechanism is the parasympathetic ganglia destruction; 3.The good FU suggests that the RF visceral ganglia destruction may prevent the innervation recovery.
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| 74-1 PULSED BIPHASIC WAVEFORM REQUIRES LESS ENERGY THAN COMMON MONOPHASIC WAVEFORM FOR CONVERSION OF ATRIAL TACHYARRHYTHMIAS Hopital de la Salpétrière Paris National Heart Hospital Sofia Bulgaria Pulsed biphasic (PB) waveform developed for external ventricular defibrillation requires less energy than common monophasic (Mn) waveform. The aim of this study was to test the hypothesis that conversion of atrial fibrillation (AF) or flutter (Fl) requires less energy with PB than Mn waveform. Method: The study population consisted of 222 patients (64% male) mean age 57±10 (27–83) mostly suffering from AF (66%). All patients failed a mean of 1.5 antiarrhythmic drugs. Arrhythmias occurred during the year (98%), the 3 months (75%) and 2 days (10%) prior to conversion. Etiologies included: valvular disease 44%, atrial dilatation (echo) 32%, coronary disease 10%, none 5%, dilated cardiomyopathy 2.7%, other 1.8%. However, 37% had clinical signs of heart failure at the time of conversion. A sequence of increasing energy shocks was delivered until a stable sinus rhythm was obtained. The starting energy was determined from body size. Results: Energy required for AF conversion was 133 versus 225 Joules ; ratio 1.69 (p<0.0001). Energy required for Fl conversion was 76 versus 208 Joules ; ratio 2.73 (p<0.0001). Less CK (x/3.5) was released and less side effects were observed with the PB waveform, in terms of block, bradycardia and arrhythmia post shock therapy. Failure rate (10%) was the same with either of the two waveforms. Conclusion: This is the first study of a large series of patients reporting the benefit of proper waveform selection for the treatment of atrial tachyarrhythmias. Half of energy level for atrial fibrillation (1/3 for flutter) was obtained and less side effects were observed with the new pulsed biphasic waveform as compared to the common monophasic waveform for conversion of atrial tachyarrhythmias.
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| 74-2 ELECTRICAL CARDIOVERSION FOR PERSISTENT ATRIAL FIBRILLATION: RESULTS OF A NATIONAL MULTICENTER STUDY X.Viñolas, J. Alegret, E.Rodriguez, X Sabaté for the Investigators of "Estudi la Cardioversió Elèctrica a Catalunya" Most of the data regarding outcome of patients (P) undergoing electrical cardioversion (CV) due to persistent atrial fibrillation (AF) comes from controlled trials. Few data exists about the "real life" clinical practice regarding antiarrhythmic drugs used, anticoagulation and maintenance of sinus rhythm. Material and Methods The "Cardioversio Electrica a Catalunya" is prospective registry of the results of CV in Catalunya (North-Est Spain- 6 M inhabitants) in P with persistent AF (>7d), and its follow-up at 3 months. Primary end-points are:maintenance of sinus rhythm, cardiovascular complications, antiarrhythmic drugs used, acute anticoagulation strategy. Thirty hospitals are participating, attending 90% of the whole population of our region. From 03/02/03 to 20/06/03, 323 consecutive patients have been included in 30 centrers. Results: mean age=65, 61% male, 48% hypertension, 21% without organic heart disease. Previous CV =20%. Efficacy of CV (sinus rhythm at discharge)=85% (median shocks=1). AAD used after CV: amiodarone 62%; IC 14%; sotalol 2%. Anticoagulation strategy used: 60% oral anticoagulation 1 month preCV. 4% Transesophageal echo guided CV. 41% of the patients are in AF after 3 m follow-up CONCLUSIONS: P cardioverted in our region are younger and have less organic heart disease compared to recent published multicenter trials, thus data of these trials should be extrapolated cautiously and in "real life" 1)AF recurrence is higher than in controlled ctrials 2) amiodarone is the most widely used AAD 3) TEE guided CV is infrequently used in our country
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| 74-3 TRANSVENOUS ELECTRICAL CARDIOVERSION IN EQUINE ATRIAL FIBRILLATION MKJ McGurrin, PW Physick-Sheard, DG Kenney, C Kerr, WJB Hanna, University of Guelph, Ontario Veterinary College, Guelph, Ontario, Canada. Atrial Fibrillation (AF) is the most common clinically significant arrhythmia in the horse (incidence 0.34–2.5%). Conventional treatment involves administration of quinidine salts. The majority of uncomplicated cases respond to treatment, but a proportion does not, while achieving therapeutic response can involve a range of side effects. Purpose: To develop and evaluate transvenous (TV) electrical defibrillation as an alternative therapeutic modality for AF in horses. Methods: Using a technique developed in research animals, thirteen (13) client-owned racehorses with AF were treated by TV defibrillation. Two, custom defibrillation catheters (Rhythm Technologies Inc.) were positioned through the right jugular vein, one in the right atrium and one in the pulmonary artery. Horses were then placed under general anaesthesia and biphasic shocks administered from an external defibrillator (LifePak 12, PhysioControl Corp.) using escalating nergies starting at 30 Joules and increasing until sinus rhythm was achieved or a maximum energy level of 300J was reached. Results: 85% (11/13) of the horses were restored to sinus rhythm. The mean duration of AF in treated horses was (7.6 +/– 8.3 wks) The mean successful energy to defibrillate was (190.9 +/– 80.1 J). No adverse effects of cardioversion attempts were observed. Horses that responded to treatment remain in sinus rhythm requiring no additional therapy and have returned successfully to training. Investigations into ideal electrode placement and methods to facilitate placement are ongoing. Conclusions: Results to date suggest tranvenous electrical cardioversion may be a realistic therapeutic option for equine AF.
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| 74-4 THE EFFECT OF PHARMACOTHERAPY ON THE RESULTS OF EXTERNAL CARDIOVERSION - IS IT DETERMINED BY ANTIARRHYTHMICS ALONE. M.Vikmane, J.Jirgensons, O.Kalejs, S.Sakne. P.Stradins University hospital/Dept.of Arrhythmology Several studies had verified the data about the influence of angiotensin system on atrial remodulation, its relation with atrial fibrillation (AF) and frequency of early relapses after external cardioversion (ECV). Our aim was to analyse the effect of possible pharmacotherapy patterns on AF relapses after ECV. Method. We compared 2 groups of pts with chronic AF (> 3 till 12 months), LA size 4.0–5.5 cm, anamnesis of AF at least 3 years, mean age 61.4 years. Group I: 128 pts 2 weeks before ECV used amiodarone (AMIO) 200mg bid and angiotensin-converting-enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), group II used just AMIO in a similar pattern. Both groups just before ECV had IV 600 mg AMIO. The same was repeated also after ECV. We compared the data: rate of AF relapses after ECV during the first hour and 24 hours, 7 and 30 days, 3 un 6 months. Individually we compared the effectiveness in groups where AF was < or > than 6 months. Results. Gr. I had a lesser number of early relapses (first hour 7.6% vs 14.9%), during 24 hours 8.8% vs 18.5%; p<0.001. Number of relapses in distant period of time continued to increase: gr. II after 30 days - 15.4% vs 28.6%, and in 6 month follow-up persistent SR was in gr. I 73.4% vs 56.4%; p<0.02. Number of relapses was greater for patients with AF > 6 months in both groups, but more in group II. Pharmacotherapy was continued also the further period of time. Conclusions. Duration of AF has an essential influence on the effect of cardioversion. ACEi/ARB, when combined with AMIO significantly affects the results of ECV and makes maintenance of SR more effective in distant period. Usage of AMIO pre- and post-EVC helps to avoid early relapses.
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| 74-5 Tissue Doppler Imaging To Monitor The Effect of Flecainide on Atrial Fibrillation Cycle Length M Duytschaever, MD, PhD, A Heyse, MD, J De Sutter, MD, PhD, R Tieleman, MD, PhD, R Colpaert, T Gillebert, MD, PhD, R Tavernier, MD, PhD, Department of Cardiology, Ghent University, Belgium. Background. Flecainide (F) prolongs atrial cycle length during atrial fibrillation (AFCL). We studied whether pulsed wave Tissue Doppler Imaging (TDI) of the atria can monitor the effects of F on AFCL. Methods. Eight pts (66±l4yrs), with AF (3 chronic, 5 acute) during an electrophysiological procedure, were studied during baseline and a l0min infusion of F (1.5 mg/kg). Transthoracic echocardiography (GE, VIVID7) performed TDI at the free wall of the right atrium (FWRA, apical 4-ch view). AFCLTDI was defined as the interval between 2 consecutive atrial events on TDI curves. AFCL was also measured from a bipolar FWRA electrogram (AFCLEGM). Results. At baseline AFCLTDI was 169±21 ms; at F 0.75mg/kg, 222±31ms (p<0.05); and at F 1.5mg/kg, 263±54ms (p<.01). Both during baseline and F, AFCLTDI correlated significantly with AFCLEGM (R2:0.76 and 0.89, p<0.05).
Conclusions: (1) Atrial tissue Doppler imaging can monitor the effect of flecainide on atrial cycle length during acute and chronic AF. (2) This novel non-invasive method is attractive to study the mechanism of chemical cardioversion in different clinical settings.
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| 74-6 TOWARD LOW ENERGY CARDIOVERSION: OPTICAL MAPPING OF RV FLUTTER TERMINATION V.Nikolski, V.Krinsky, A.Pumir, I.Efimov Biomed Eng, Case University, Cleveland, OH 44106 USA. Institut Non Linéaire de Nice, 1361 route des Lucioles, 06560, Valbonne, France Theoretical limit for diminishing energy of cardioversion is {small tilde} 400 times (ref.1) compared to the standard el. field E{small tilde} 10V/cm. We investigated experimentally this approach and mechanisms of the cardioversion. Methods.Stable ventricular flutter (VFl, cycle length of 117±16 ms) was induced in superfused preparations of rabbit right ventricle (RV) free wall (n=5). Optical mapping with potentiometric dye di-4-ANEPPS was used during VFl and cardioversion (E= 0.3 -2.0 V/cm; duration = 6 ms). ResultsOptical mapping revealed that the reentry circuits were pinned to the Trabeculae of RV endocardium. Immunohistochemistry showed that Connexin 43 (Cx43) expression was preserved at the endocardium and trabeculae above 0.2 mm from the endocardial surface, similar to the acute phase of infarct. Field stimulation applied during the vulnerable window VW (7±3 ms) of the cycle terminated flutter at field strengths 1.3±0.3 V/cm. VFl termination was achieved by excitation near the core of reentry (35% cases) or by changing repolarization dynamics at the reentry pathways (65% cases).Optical mapping revealed field-induced virtual electrode polarizations at tissue anchoring reentry. Conclusions. Field stimulation with E {small tilde}1 V/cm applied at precise vulnerable phase of VFl can terminate arrhythmia by induction of virtual electrode polarizations at the structures anchoring reentry. It corresponds to diminishing defibrillation energy {small tilde}100 times. Ref.1.S.Takagi et al, A physical approach to remove anatomical reentries. J.Theor.Biol,2004, accepted.
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| 88-1 Evaluation of the effectiveness of a new Beat by Beat capture Function to save pacing energy. C. Alonso, °A. Savouré, °°H. Ranaivoson, °°C. Casset, °F. Anselme. InParys, St Cloud, °University hospital, Rouen, °°ELA Medical, Le Plessis-Robinson, France. Automatic beat-to-beat capture functions have been designed in order to minimize delivered pacing energy while maintaining a maximum safety, delivering an immediate back-up spike in case of loss of capture. The objective of this study was to estimate the lowering of ventricular pacing amplitude allowed by such a function, as compared to manual amplitudes usually set in routine practice. Methods: An automatic ventricular pacing threshold test is launched every 6 hours to measure the Pacing Threshold PTi (i=1 for first test, 2 for test done after 6 hours,....). From the actual PTi the function calculates 2 values: the Pacing Amplitude (PAi)=max(1; PTi±0.5), and Safety Amplitude (SAi)=max(2.5; PTi*2). The function uses preferably PAi and checks capture efficacy after each paced beat. In case of loss of capture a back-up spike is delivered and SAi will be used up to the next threshold measurement. We estimated the minimum and maximum Delivered Ventricular Amplitude (DVA) from the pacing data stored by the pacemaker at 1-day (with a 24-hour Holler record) and after 1-month follow-up. We compared this value with the pacing amplitude set by the physicians using routine manual settings, the Manual Pacing Amplitude (MPAi)=max(2*PTi; 2,5). Results: We reviewed the data available from 55 patients implanted with a Talent 3 DR pacemaker (ELA Medical, France): 32 files were complete at 1-day and 15 at one-month follow-up for the purpose of the analysis. Results are the following:
No loss of capture and no ventricular pause was documented on Holter records. DVA was lower than MPA at both visits. Conclusion: This new beat-to-beat capture function allows a significant lowering of pacing amplitude compared to manual settings, while preserving a 100% safety.
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| 88-2 FUSION BEAT DETECTION IN ICDS WITH A NEW VENTRICULAR AUTOMATIC CAPTURE DETECTION ALGORITHM Giuseppe Boriani1, Johannes Sperzel2, Maura Biffi1, Thorsten Schwarz2, Andreas König3, Sara Temporin3, Yanting Dong4 and Scott Meyer4, 1Kerckhoff Klinik Bad Nauheim, Germany, 2University Hospital, Bologna, Italy, 3Guidant Europe, Diegem, Belgium, 4Guidant Corporation, St.Paul, MN, US. This study evaluated a new developed automatic capture verification scheme in respect to the discrimination of captured (C), fusion (F) and non-captured (NC) beats. The algorithm uses evoked response detection utilizing a sensing vector from right ventricular shocking coil to Can. Methods: Patients undergoing ICD implant or replacement were enrolled into this study. An external device for pacing and data acquisition was used to provoke ventricular fusion beats. WI patients were paced close to their intrinsic underlying rhythm, DDD patients were paced close to their intrinsic AV interval. Various vectors of surface ECG and wideband filtered intracardiac electrograms were recorded for off-line analysis. Each event was classified visually and by the automatic detection algorithm. The algorithm performance was then evaluated by comparing the classification results. Results: 27 patients (22m/5f; 63.8±12.5 years) were analyzed. Device and lead demographics: 18 DDD/9 VVI; 16 dedicated BP/11 integrated BP leads; 18 acute/9 chronic (3.7±2.0 years) leads. In total 2064 beats were analyzed, including 1477 F beats and 587 C beats. Sensitivity and specificity of the algorithm was 99.5% and 99.0%. Wrong classification occured to 7 true F beats (0.5%) which were classified as C beats, 6 C beats (1.0%) were identified as F. No C or F heats were detected as NC beats. Conclusion: The algorithm is very effective in the detection of fusion beats. It can be potentially used in many ICD applications that need accurate fusion detection, e.g., automatic capture verification.
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| 88-3 AUTOMATIC ATRIAL CAPTURE MANAGEMENT (ACM) IN DUAL CHAMBER PACEMAKERS Sperzel, Johannes, Compton, Steven, Milasinovic, Goran, Mead, Hardwin, Smith, Timothy W., Brandt, Johan, Haisty, Wesley K., Bailey, J.Russell, Roelke, Marc, Simonson, Jay, Ahn, Chul, Henk, Dieteren, Worldwide EnPulse Investigators. Kerckhoff Klinik, Bad Nauheim, Alaska Heart Institute, Anchorage, Clinical Center of Serbia, Belgrade, Sequoia Hospital, Redwood City, Washington University, St. Louis, Lund University Hospital, Lund, Wake Forest University, Winston-Salem, Mid-Carolina Cardiology, Charlotte, Arrhythmia and Pacemaker Consultants, West Orange, Cardiovascular Consultants, Ltd., Minneapolis, Bakken Research Center, Maastricht. Purpose: This study was performed to evaluate the accuracy of ACM, a new algorithm incorporated in the Medtronic EnPulseTM pacemaker. Method: ACM and manual atrial threshold measurements were compared at 1-month post implant. Ambulatory ACM measurements stored in the device diagnostics were analyzed to further assess ACM accuracy and patient applicability. Results: 125/200 implanted patients (pts) had validated manual and ACM tests. ACM threshold tests demonstrated a mean threshold of 0.603V vs. 0.588V for the manual test with a mean difference of 0.015 ± 0.070V (90% confidence interval of 0.005, 0.025). There were zero instances where the threshold difference for an individual patient was outside the predefined range of clinical equivalence (-0.25 V to +0.5 V). Ambulatory ACM measurements were made in 192/200 pts prior to the one-month visit. The ambulatory ACM measurement demonstrated a mean threshold of 0.630V vs. 0.599V for the manual test with a mean difference of 0.031V ± 0.112V (90% confidence interval of 0.016, 0.046). ACM induced no atrial arrhythmia. Conclusion: Atrial capture management is safe and accurate, and clinically equivalent to manual threshold measurements.
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| 88-4 EVALUATION OF ATRIAL EVOKED RESPONSE FOR CAPTURE DETECTION WITH HIGH POLARIZATION LEADS J Sperzel1. G Boriani2, M Biffi2, J Snell3, J Scheiner4, E Park3; Kerckhoff-Klinik Bad Nauheim1, Germany, Inst of Cardiology2, Bologna, Italy; St Jude Medical3, Sylmar, USA and St Jude Medical4, Eschborn, Germany. Objectives: Beat-by-beat AutoCaptureTM based on analysis of the evoked response (ER) can be confounded by polarization (POL) caused by the pacing pulse. This study seeks to measure lead POL in human subjects with chronic high POL atrial (A) leads. The motivation for this study is to determine if lead POL can be measured using an integral of the negative portion of A paced ER (AERI). A further objective is to determine if a screen for high POL A leads can be specified. Method: A IEGM signals from 30 human subjects with AffinityTM or IntegrityTM pacemakers (median of 76±36 years of age; 18 male, 12 female) were analyzed an average 34.1 months post implant. Patient selection was based on the implanted A lead model. The surface ECG and AIEGM signals were captured and recorded by the APS 3510 programmer during a series of conventional A threshold searches. The data was then transferred to a PC for analysis. Unipolar A pacing with uni and bipolar AIEGM signals as well as bi pacing with uni AIEGM signals were evaluated. A total of 147 capture thresholds were recorded. Atr. capture thresholds ranged from 0.25V to 2.75V with an average of 1.04V Results: Each evoked response was evaluated using AERI in a 36 millisecond window following the A pulse. POL was estimated as a linear function of pulse voltage using the AERI of capturing beats from the threshold search IEGM data. The 147 threshold search data sets included leads with 3 distince electrode materials, the median POL (AERI as a function of voltage) for each is:
A fourth material was omitted due to a small sample size - 1 Pt. Conclusion: These results indicate that POL can be measured using AERI as a function of pulse voltage. Furthermore, this POL measure can be used to screen for high POL leads which are ill suited for the Atrial AutoCaptureTM algorithm.
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| 88-5 LONG TERM LEFT VENTRICULAR PACING BY AUTOCAPTURE: FEASIBILITY AND EFFICACY Biffi M, Boriani G, Bertini M, Martignani C, Valzania C, Diemberger I Institute of Cardiology, University of Bologna, Italy We investigated the feasibility and efficacy at long term of left ventricular (LV) pacing by autocapure, and the trend of transvenous epicardial LV pacing threshold. METHODS: Five patients (age 68.6+/–7.4 years, range 60–80) with sick sinus syndrome, complete left bundle branch block and dilated cardiomyopathy (left ventricular EF = 41+/–6%) with class II heart failure received a DDDR pacemaker with autocapture (Insignia I 1290, GUIDANT). This device checks ventricular threshold daily, and is able to provide its detailed trend over time. All the patients received a bipolar atrial active fixation lead. An Attain 4193 lead (MEDTRONIC) for transvenous left ventricular pacing was placed in a posterolateral or anterolateral branch of the coronary sinus and connected to the ventricular port of the pacemaker in all the patients. Autocapture was turned on at the end of implantation, and performed satisfactorily in all the patients. Patients were controlled at 3 months interval to observe the Autocapture performance and the trend of LV pacing threshold. RESULTS: Appropriate function of Autocapture was observed in all 5 patients with LV thresholds ranging form 0.8 to 1.3 V at 0.4 ms. Autocapture was able to maintain ventricular output between 1.3 and 1.8 V. No sudden increase of LV threshold was seen at an average follow up of 8.4+/–2.8 months (range 7–14). A slight increase of LV threshold (from 0.8 to 1.3 V) was observed in 3 patients around the 2nd month post implantation, with a complete return to former threshold (0.6 to 0.9 V) by the fourth month. CONCLUSIONS: Transvenous LV pacing by autocapture is feasible and effective with unipolar leads, and can decrease the energetic cost in Cardiac Resynchronisation devices.
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| 88-6 AN EVOKED RESPONSE MORPHOLOGY BASED ALGORITHM FOR RIGHT & LEFT VENTRICULAR CAPTURE VERIFICATION P. Diotallevi, A.P. Ravazzi, G. De Marchi, E. Gostoli, *C. Militello, *H. Kraetschmer, Division of Cardiology, Osp. SS Antonio e Biagio, Alessandria, Italy. *Biotronik, Erlangen, Germany. Background: Cardiac resynchronization therapy relies on myo-cardial capture in both ventricles at each heart beat. A pacemaker assuring right and left ventricular capture through automatic output adjustment would support patient safety and quality of life. We investigated the feasibility of an evoked response (VER) morphology based algorithm for capture verification in both ventricles. Methods: Right ventricular (RV) and left ventricular (LV) VER were recorded from 16 patients (mean age 71±8 years, 2 female and 14 male) during the implant of a biventricular (BiV) device. Leads of different companies (Medtronic, Guidant, Biotronik, St. Jude) were tested. Pacing and data recording were performed by an external device (Logos, Biotronik), ECG and VER were recorded under different pacing conditions for 10 s each: RV pacing, LV pacing, and BIV pacing with different interventricular delays (-60 ms, -20 ms, 0 ms, 20 ms, 60 ms). VERs were classified offline for capture and non-capture by the morphology based algorithm. This classification was confirmed or rejected manually with the aid of ECGs.
Results: A total of 2647 LV and 2481 RV paced events-were collected. The results are summarized in the table. The sensitivity of the algorithm was 91.0% (for RV) and 97.6% (LV), while the specificity was 93.3% (RV) and 94.0% (LV). The lower sensitivity in the RV was a consequence of the signal blanking in both channels in conditions of BiV pacing with an intraventricular delay
Conclusions: The signal morphology based algorithm for RV and LV capture and non-capture classification performed safely and efficiently with all leads tested in the study.
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| 89-1 PRELIMINARY RESULTS OF THE GERMAN ISOFLEX LEAD REGISTRY U. Lotze1, S. Fischer2, A. Lang3, C. Papenberg4, and M. Klutmann5 on behalf of the German IsoFlex Registry. 1Krankenhaus Waltershausen-Friedrichroda, 2Altstadt-Krankenhaus Magdeburg, 3Erfurt, 4Krankenhaus Düsseldorf Benrath, 5Krankenanstalten Düren, Germany Purpose: The aim of this study is to evaluate the long term pacing and sensing characteristics of the IsoFlex S pacing leads, models 1636T and 1646T, in routine follow-up. Methods: The IsoFlex S lead models 1636T or 1646T (St. Jude Medical, Sylmar USA [SJM]) are implanted in the right ventricle together with a pacemaker Integrity or Identity (SJM each). Up to date, 63 patients (27 men, 23 women, 12 not reported; mean age 73±8 years) were enrolled into the study. At each routine follow-up, AutoCapture (AC) threshold, evoked response (ER) sensing and automatic R-wave measurements are performed until 14 months after implantation.
Conclusion: These preliminary results suggest that the IsoFlex S leads are suitable for ventricular pacing with low capture thresholds, which may increase pacemaker longevity without reducing patient safety.
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| 89-2 DEFLECTABLE SHEATH-DELIVERED LUMENLESS PERMANENT PACEMAKER LEADS CLINICAL STUDY RESULTS 1 Randy A. Lieberman MD, 2George H. Crossley MD, 3Christopher S. Simpson MD, 4Wk Haisty MD, 5Katie Schaaf. 1Harper Hospital, Detroit, MI; 2Baptist Hospital, Nashville, TN; 3Kingston General Hospital, Kingston, On, Canada; 4Wake Forest University School of Medicine, Winston-Salem, NC; 5Medtronic, Inc., Mpls., MN Purpose: Transvenous permanent pacing leads implanted utilizing a deflectable delivery sheath have desirable features that may improve reliability: no stylet lumen, smaller French size with redundant insulation, cable running from the helix to the connector pin, and the lead position can be more specifically directed. The Medtronic SelectSecure lead is sheath-delivered, bipolar, fixed screw, steroid-eluting lead with a 4.1 Fr. lead body and has no stylet lumen. The Medtronic SelecteSite sheath has a single 7.5 Fr. lumen and features a handle-controlled deflecting distal section. Methods: The study was comprised of 264 dual chamber implants (177 analyzed). The primary objectives of this multicenter clinical study are: safety (lead-related complications and events) and effectiveness (pacing and sensing) from implant through 3 months post implant. Results: Electrical Data- Bipolar Pulse width threshold at 2.5V, ms A- PHD.06 ± .10, 3 Mon FU.08±.10; V- PHD.04 ±.03, 3 Mon FU.10 ±.08 Sensing, mV—A- PHD2.9 ± 1.4, 3 Mon FU3.1 ± 1.6; V- PHD9.4 ± 4.1, 3 Mon FU10.3 ± 5.2 Impendance—A- PHD656 ± 172, 3 Mon FU580 ± 65; V- PHD723 ± 137, 3 Mon FU638 ± 108 *A=Atrial, *V=Ventricular *PHD = Pre-hospital discharge, *FU = Follow-up Lead Related Complications: Atrial 0.6% - 2 complications-2 dislodgements. Ventricular 5.7% -10 complications-2 elevated thresholds, 4 perforations, 3 dislodgements, 1 loss of capture. Conclusions: The lead-sheath system is feasible and safe, improving lead placement in traditional and new pacing sites.
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| 89-3 A SCREW-IN ELECTRODE COMPARED IN 3 PATIENT GROUPS: SICK SINUS SYNDROME, AV BLOCK AND CRT Jan CJ Res, Marcel JJA Bokern, ZMC_De Heel, Zaandam and Waterland Hospital, Purmerend, NL. The ELOX (Biotronik EX 53-BJP or 60-BP) is implanted as a standard electrode in the atrium, because of its ease of handling and active fixation. It was also implanted in patients with CHF, who were candidates for CRT. In some individual CRT patients we found high sensing values. Therefore we compared the pacing and sensing characteristics of this lead in 3 patient groups: pts with sick sinus syndrome (SSS, n=23), high degree or complete AV block(AVB, n=27), and CHF patients, with cardiac resynchronisation therapy (CRT, n=26) METHODS: bipolar pacing and sensing values were measured by the ERA 300B during implantation and via the pacemaker (SSS and AVB: Philos Inos DR and CRT: Stratos LV, all Biotronik, Germany) during follow up till 6 months. RESULTS: The p wave amplitude in the CRT group was a not significant higher 2,9 ± 1,7 vs 2,3 ± 1,4 mV at implant and at 6 Months differences were also small and not siginificant 3,6 ± 2,4 vs 2,9 ± 2,3 (p=NS). The pacing threshold at implant was similar in the SSS, AVB and CRT groups, respectively 0,8 ± 0,4 vs. 0,9 ± 0,5 vs. 1,1 ± 0,8 V. At 6 months no diofference at all was seen. Thge pacing impedance at in the CRT group was higher: 610±266 vs AVB: 478±111* or SSS: 491±210* Ohm (*vs CRT, p < 0,05) at implant, which difference still was present at 6 month, CRT 494±175 Ohm vs 370 ± 55# (# vs CRT, p < 0,04). CONCLUSION: Sensing and pacing characteristics are identical in the 3 groups, except for the pacing impedance, which is higher in patients with CRT vs patients with a bradycardia pacing indication, either SSS or advanced AV block. The nature of this higher impedance in CRT patients needs further investigation.
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| 89-4 LONG TERM FOLLOW-UP OF MEROX: MULTICENTRIC STUDY GROUP. E. Blache (Istres), A. Bonneau (ChateauFoux), O. Citme (Caen), B. Degand (Tours), P. Deutsch (St Malo), J. Deyrolle (Saint Palais), H. Dorey (Caen),N. Echaidi (Saintes), L. Gencel (Merignac), J.L Groulier (Bayonne), M. Hadid (Beziers), H. Lacroix (Evecquemont), B. Lahitton (Dax), L. Larouchi (Bayonne), C. Mathurin (St Lô), V. Mazoyer (Avignon), P. Mermet (Marseille), T. Minviole (Saint Palais), C. Moini (Antony), E. Parrens (Bordeaux), P. Pujadas (Nimes), P. Scanu (Caen), J. Turmel (Niort), J.L. Vaides (Calais), C. Valantin (Pontoise), G. Vignozzi (Roubaix) STUDY OBJECTIVE: multicentric evaluation of acute and follow-up parameters of the Biotronik fractally coated Merox 60 BP(MEX60BP, 1.3 mm_) ventricular pacing lead. MATERIAL and METHODS: 176 patients (112 M, 64 F mean age 77 ± 10) have been implanted with MEX60BP. Impedance, voltage pacing threshold (at 0.1ms 0.4 ms and 1.0ms) and R wave amplitude were measured at implant and follow-up, FIRST RESULTS:
CONCLUSION: The MEX60BP lead provides low acute and chronic pacing thresholds with stable R wave amplitudes. The performances of this fractally coated lead provide a lower current drain and thus should increase pacemaker longevity.
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| 89-5 IMPLICATION OF PACING IMPEDANCE MEASUREMENT ON ELECTRODE STABILITY. A ONE YEAR FOLLOW UP WITH THE BIPOLAR HIGH IMPEDANCE ELECTRODE CAPSURE Z 5054 NOVUS Cordula Kloppe1, Axel Kloppe2, Horst Neubauer1, Bernd Lemke2, Andreas Mügge1 1Department of Cardiology, St. Josef-Hospital, University Clinic, Ruhr-University Bochum, Germany 2Department of Cardiology and Angiology, Klinikum Luedenscheid, University Bonn, Germany Purpose: Bipolar electrodes allow better sensing than unipolar but little is known about parameters for long term stability. Methods: The bipolar steroid coated high impedance electrode Capsure Z 5054 Novus was implanted in 166 patients. The follow up was performed over a one year period. Results: During implantation the mean impedance of all implanted electrodes was 1272 W ± 294, the mean threshold was 0.31 V/0.5 ms ± 0.15 and the sensing of the R amplitude was 14.8 mV ± 5.4. In 24 patients (14.5%) it was not possible to reach a sufficient impedance that was higher then 1000 W (mean 862W ± 82), even though there was a good sensing (13.9mV ± 5.4) and a low pacing threshold (0.34V/0.5 ms ± 0.3). After 1 year the mean impedance of all patients was 1032 W ± 207, the mean threshold was below 0.5 V at 1.0 ms and the mean sensing of the R amplitude was 14.62 ± 5.98 mV. In the described 24 patients the mean impedance was 848 W ± 130, the mean sensing was 9 mV ± 5. 4 and the threshold was 0.94 V/0.82 ms ± 0.8, which is a sign of micro dislocation. In 2 of these patients a revision of the electrode had to be performed. In all other cases with initially high impedance values, no dislocation or pacing impairment was seen. Conclusion: The follow up confirmed the cases of initially measured low values of the impedance with a significant increase of the pacing threshold and a decrease in R wave sensing. The impedance in these electrodes is a strong indicator for predicting a reliable and durable electrode position.
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