All 157 subjects with final TIMI 3 flow had continuous 12-lead electrocardiography with simultaneous Holter recording initiated prior to PCI for continuous ST-segment recovery and quantitative VA analyses. Ventricular arrhythmia bursts were detected against subject-specific background VA rates using a statistical outlier method. For temporal correlations, timing and quality of reperfusion were defined as first angiographic TIMI 3 flow with ≥50% stable ST-segment recovery. Almost all subjects had VAs [156/157 (99%)], whereas VA bursts during or subsequent to reperfusion occurred in 97/157 (62%). The majority of VA bursts (72%) arose within 20 min of reperfusion (95% CI: 26.7, 72), with onset at a median of 4 min post-reperfusion (IQR: 0–43) Bursts comprised a median of 1290 ventricular premature complexes (VPCs) (IQR: 415–4632) and persisted for a median of 105 min (IQR: 35–250). Most background VAs occurred as single VPCs; bursts typically comprised runs of three or more VPCs. Subjects with bursts had higher absolute peak ST segments and more frequent worsening of ST elevation immediately after reperfusion.

Ventricular arrhythmia bursts temporally associated with TIMI 3 flow restoration and stable ST-segment recovery (reperfusion VA bursts) can be precisely defined in subjects with anterior STEMI and may constitute a unique electric biosignal of myocellular response to reperfusion.

A nation-wide population-based cohort of 8777 patients with AAI- or DDD-mode pacemakers was followed during 12 years. The cohort was linked to national healthcare and census registers. Patients with DDD pacing and without any pre-implant admission for atrial fibrillation or flutter had an increased risk of post-implant fibrillation or flutter, in relation to corresponding AAA patients [hazard ratio (HR) = 1.30; 95% confidence interval (CI) 1.10–1.52]. A slight increase in the risk of any cardiovascular disease (HR = 1.07; CI, 1.00–1.15), and all-cause mortality (HR = 1.12; CI, 1.00–1.25), was seen among DDD patients, in relation to AAI patients, but there was no significant difference in the risk of ischaemic or unspecified stroke (HR = 1.14; CI, 0.94–1.37). Among DDD patients, the all-cause mortality did not differ from the general population [standardized mortality ratio (SMR) = 1.04; CI, 0.98–1.11]. Patients with AAI, however, had a decreased all-cause mortality risk (SMR = 0.89; CI, 0.82–0.97).

Our results support AAI as the preferred mode of pacing in patients with sinus node disease, and a normal AV node function.

Consecutive post-mortem cases of adult SCDs presumed to be caused by a ventricular arrhythmia over 12 months (2002–03) from a defined catchment population, Southampton, UK (n = 443 824 adults aged ≥16 years). Pathological data were extracted from the post-mortem reports. Hospital and general practice (GP) notes provided data on previous symptoms, investigations, and cardiac disease history. Two electrophysiologists judged the appropriateness of each case for an ICD against National Guidance. Two hundred and fifteen cases met the inclusion criteria and lived within the catchment area. Agreement between experts on appropriateness for an ICD in those aged <80 years was good (kappa score of 0.64). Only one case (<1%) was considered appropriate for an ICD without requirement for further investigation. Forty-nine per cent of cases were considered to have required further cardiac investigations to determine appropriateness; these were mainly heart failure patients who had suffered a myocardial infarction (MI). Forty per cent of cases had no previous clinical evidence of confirmed or suspected heart disease. However, pathological data showed that 51% of cases had suffered a previous MI.

Two-fifths of SCD victims had no recorded health service contact that would indicate increased risk of SCD within their lifetime. A large number of patients suffered previous cardiac events or symptoms suggestive of increased SCD risk but were not referred for further investigations. There is a need for better care pathways for patients post-MI to identify those requiring an ICD. The impact on the ICD rate of undertaking these extra investigations is uncertain.

We evaluated children with frequent PVCs and anatomically normal hearts (n= 59; 35M/24F) by 12-lead ECG, echocardiography, Holter recording, and an exercise test. Age at the first visit was 7.1 ± 4.3 years (mean ± SD), and follow-up was 3.1 ± 3.1 years. We could evaluate each child for 2.5 ± 1.5 times. Premature ventricular contraction with left bundle branch block was seen in 41% of the children; PVC-RBBB in 36%; and undetermined in 23%. Mean percentage PVCs in the Holter recording decreased (14.3 ± 13.7% in the age group 1–3 years to 4.8 ± 7.2% in the age group ≥16 years; P= 0.08). Mean percentage PVC-LBBB did not change (12.3 ± 21.4 vs. 11.7 ± 5.5%), whereas PVC-RBBB decreased (16.3 ± 4.2 to 0.6 ± 1.4%; P < 0.02).

We conclude that there is a difference in the natural history between PVC-LBBB and PVC-RBBB in children with an anatomically normal heart. Premature ventricular contraction with right bundle branch block disappears during childhood. Follow-up of these children seems not necessary. Premature ventricular contraction with left bundle branch block does not disappear and, therefore, it may be necessary to follow these children even during adulthood.

We describe nine patients (four males and five females) in whom sarcoidosis manifested as ventricular tachycardia (VT). The age of the patients was 53 ± 10 years (range 33–68). The disease was diagnosed by endomyocardial biopsy in eight patients and by lymph node biopsy in one patient. The presenting arrhythmia varied from non-sustained VT to incessant VT and ventricular fibrillation. All patients received implantable cardioverter defibrillator (ICD) and anti-arrhythmic medication. High-dose steroid treatment was used in eight cases. During the follow-up (50 ± 34 months), five patients underwent appropriate ICD therapies and non-sustained VT episodes were detected in four patients. Two patients developed incessant VT, which was treated by catheter ablation. One patient was referred for heart transplantation.

Our data indicate that sarcoidosis can manifest as VT without any detectable systemic findings. This makes sarcoidosis an important diagnostic consideration in patients with VT of unknown origin. Arrhythmia control in cardiac sarcoidosis is difficult, and all modern treatments including high-dose steroids, anti-arrhythmic drugs, ICD, and catheter ablation are needed to suppress the arrhythmias.

The follow-up results of 264 leads from 184 patients were evaluated using pacemaker follow-up data. Underlying conditions, implant data, and lead features were evaluated for the analysis of lead fracture. During a mean follow-up of 72.8 ± 39.7 months (range 3.2–160.6, median 70), lead fracture developed in 19 leads (7.2%) from 18 patients. The mean duration between implantation and lead fracture was 57.3 ± 35 months (range 6.8–130, median 51). All fractures occurred in the leads implanted by the infraclavicular subclavian approach. Cumulative survival at the end of 5 years was 92.7% in terms of lead fracture. None of the patient-related risk factors correlated with lead fracture. Multivariate analyses of lead-related risk factors revealed a significant correlation only between lead fracture and fixation mechanism (P < 0.05).

Our results indicated that none of the patient-related risk factors was correlated with lead fracture. Among lead-related risk factors, only the fixation mechanism was found to be correlated with lead fracture; thus, it seems that passive fixation mechanism is safer in terms of lead fracture. Although all fractures occurred in the leads implanted by the intrathoracic subclavian approach, statistical analysis revealed no significance for this parameter. The effect of the extrathoracic approach should be investigated in a large group of patients.

We analysed outcomes with respect to death, ICD therapy delivery, and complications for 20 patients with repaired TOF and 39 dilated cardiomyopathy (DCM) patients followed up at a UK teaching hospital. All TOF patients had clinical ventricular tachycardia (VT), electrophysiological study-inducible VT, or previous arrest due to tachyarrhythmia and received dual-chamber devices with individualized atrial detection algorithms. Tetralogy of Fallot patients were younger than DCM patients, but follow-up duration was not different between the groups. Tetralogy of Fallot patients were more likely to have experienced oversensing (45 vs. 13%; P < 0.02), inappropriate anti-tachycardia pacing delivery (20 vs. 2%; P < 0.05), and inappropriate cardioversion (25 vs. 4%; P = 0.06) than DCM patients and less likely to receive appropriate therapies than DCM patients. The death rate in TOF patients was significantly lower than that in DCM patients (5 vs. 21%; P < 0.05).

Tetralogy of Fallot patients have a higher risk of inappropriate therapies and other complications yet a lower incidence of appropriate therapies from their ICD than DCM patients. Further research into identification of factors predicting SCD in TOF and the benefits of ICD implantation is essential given the potential complications of ICD implantation in young congenital heart disease patients.

A total of 260 patients with HM ICDs were monitored for a mean of 10 ± 5 months. Time to HM events [medical (ventricular tachycardia/ventricular fibrillation) and technical (ICD system integrity)] since ICD implantation and since the latest in-clinic follow-up was analysed. Mean number of HM events per 100 patients per day was calculated, without and with a 2-day blanking period for re-notifying the same type of event. About 41.2% of the patients had HM events (38.1% medical, 0.8% technical, and 2.3% both types). Probability of any HM event after 1.5 years was 0.50 (95% confidence interval: 0.42–0.58). More than 60% of new HM event types occurred within the first month after follow-up. A mean of 0.86 event notifications was received per 100 patients per day or 0.45 with the 2-day blanking period.

Home monitoring is feasible and associated with an early detection of medical and technical events.

We analysed the procedural characteristics, acute success, and recurrence rates of 160 consecutive patients treated with cryoablation for the AVNRT and followed up for 18 months. Mean procedural time was 119.1 ± 3.7 min, with an average of 4.6 ± 0.2 Cryo lesions and an acute procedural success rate of 93%. Recurrence rates were 19 (11.9%) cases and were significantly higher in the 4 mm cryocatheter-treated group (12/59, 16.9%), compared with the 6 mm cryocatheter-treated group (9/101, 6.9%, P = 0.01). Recurrence rates were greater where slow pathway block was not achieved 8/12 (66.7%), compared with complete slow pathway block 11/129 (8.5%, P < 0.0001). Recurrence was significantly more likely if atrial echo beats were still present after cryoablation, 12/130 (9.2%) patients with no recurrence vs. 7/19 (36.8%) patients with recurrence (P < 0.0001).

Cryoablation is a safe and efficacious treatment for AVNRT. Complete slow pathway block is associated with long-term success, together with the use of the larger 6 mm cryocatheter. There is always a risk of heart block with radiofrequency ablation, although this experience confirms previous findings that the risk with Cryo is zero.

The multicentre FOLLOWPACE study prospectively collected data during implantation and follow-up of 1526 patients who received a PM for the first time. A total of 4914 follow-up visits were studied. Mean follow-up was 394 days with a mean of 3.2 visits per patient. At all follow-up visits, the battery condition was tested in >93%, the stimulation threshold in >91%, and sensing in >87%. The pacemaker parameters as stimulation and sensing thresholds, lead impedances, and percentages of pacing remained stable over time, but these values did depend on the lead location, lead fixation, and pulse duration. The majority of PM (re-)programming was performed during implantation and/or shortly before hospital discharge (50%). PM re-programming during follow-up was most frequently performed by the PM technician alone (95%).

Crucial PM parameters are regularly checked. Re-programming of PM parameters declined during the first year after PM implantation. The majority of PM checks were carried out by the PM technician, indicating the major influence of the allied professional on the quality and safety of the pacing therapy.

To investigate the presence and extent of PV potentials in patients with and without AF.

Circumferential catheter recordings at the PV ostia were obtained from 10 patients with paroxysmal AF and 9 with concealed Wolff-Parkinson-White (WPW) syndrome without history of AF. Typical PV potential was defined as either rapid deflections that separated from atrial deflection with a time delay in-between, or multiphasic, continuous or fractionated potentials. The presence of PV potentials was verified during sinus rhythm and during atrial pacing at the distal coronary sinus for the left PVs or at the right atrial appendage for the right PVs. To quantify the extent in which the PV potentials were recordable, the number of PVs with typical PV potentials recordable was counted. The time interval from the onset to the end of the electrograms recordable at the PV ostium (A–PV interval) was measured, and the maximal and mean of this interval were obtained. Typical PV potentials were recorded in 31 of 34 PVs (91%) in patients with AF, but in 4 of 36 PVs (11%) in patients with concealed WPW. A narrow, biphsic or triphasic, potential was recorded in 3 of 34 PVs (9%) in patients with AF, but in 29 of 36 (81%) PVs in patients with concealed WPW. The maximal and mean A–PV intervals were significantly longer in patients with AF (71 ± 24 and 49 ± 13 ms) than in patients with concealed WPW syndrome (33 ± 14 and 25 ± 6 ms).

In patients with AF, typical PV potentials with marked conduction time delay were almost invariably recordable at the PV ostium, but in patients without a history of AF, merely simple, narrow potentials were found. These findings support the involvement of conduction delay and re-entrant activities around the PV ostia in the genesis and/or perpetuation of AF.

This study included 12 patients with EAT. During tachycardia, earliest atrial activation was recorded at the His site at a standard catheter setting. Activation mapping was performed in the right atrium and along the mitral annulus and at the aortic root after retrograde insertion of the ablation catheter over the ascending aorta. In five patients, earliest atrial activation was recorded at the mitral annulus (in two patients at the superior-lateral annulus and in three patients at the inferior-medial annulus). In four of these patients, EAT could be successfully treated by RF ablation through the retrograde approach, whereas in one patient, a transseptal puncture was performed in order to achieve a stable catheter position. In seven patients, RF ablation at the non-coronary aortic sinus eliminated the tachycardia. During a follow-up period of 14 ± 8 months, there was no tachycardia recurrence.

In patients with EATs and early atrial activation at the His site, tachycardia may arise in the non-coronary aortic sinus or from the mitral annulus. Radiofrequency energy ablation can be performed through a retrograde approach in the majority of these patients and is safe and effective in eliminating this type of tachycardia.

This prospective study involved 23 cardiologists established in office practice in Geneva. Enrolment started on 1 January 2005 and ended on 31 December 2005. Consecutive patients were included if they were >18 years and had AF documented on an ECG during the index office visit or during the preceding month. In this survey, 622 ambulatory patients were enrolled (390 males and 232 females; mean age 69.8 ± 11.8 years). The prevalence of paroxysmal, persistent, and permanent AF was 35, 18, and 47%, respectively. Underlying cardiac disorders present in 513 patients (82%) included hypertensive heart disease (30%), valvular heart disease (27%), coronary artery disease (18%), and myocardial disease (11%). A rate-control strategy was chosen in 53% of the patients (331/622). The mean CHADS₂ score was 1.43 ± 1.24, and 458/622 patients (73.6%) had a CHADS₂ score ≥1. Among patients with an indication to oral anticoagulant therapy (OAT), 88% (403/458) effectively received it. The rate of OAT was closely correlated with an increasing CHADS₂ score, particularly with patients age (72, 81, and 87% for patients <65, 65–75, and >75 years of age, respectively). True contraindication for OAT was present in 4% (18/458). In the low-risk group (CHADS₂ score = 0), 58% were prescribed OAT, but in 37% of them only for a short period of time (cardioversion/ablation). After a follow-up of 396 ± 109 days, 72% of the study group (410/570) was still treated by OAT. During follow-up, 23/570 patients died (4%), essentially from a cardiovascular cause (15/23), 15 had a non-lethal embolic stroke (2.7%), and 8 had significant bleeding complications (1.5%).

This study shows one of the highest OAT prescription rates for AF reported until now and demonstrates how successfully guidelines can be applied in the real world. A definite overinterpretation of current guidelines is observed in low-risk patients with AF. True contraindication for OAT (4%) and significant bleeding during OAT (1.5%) were rare.

Four groups of subjects underwent tilt testing (TT) during the passive phase and, if negative, after nitroglycerin administration: Group I, 20 subjects with a history of syncope and positive passive TT; Group II, 23 subjects with a history of syncope and TT positive after nitroglycerin; Group III, 23 subjects with a history of syncope and negative TT; and Group IV, 20 normal control subjects. Heart rate, systolic, diastolic, and mean blood pressure, stroke volume, cardiac output, and total peripheral resistance were computed from pressure pulsations (Modelflow). The demographic data and the values of the haemodynamic variables in the supine position did not differ significantly among the four groups. The per cent changes in these variables did not differ significantly among the four groups after 2 and 5 min of TT and among Groups II, III, and IV, 2 min after nitroglycerin administration.

Young/middle-aged subjects with VVS have a normal measured haemodynamic response to orthostatic stress; therefore, the vasovagal reflex is not secondary to an impairment of the primary vasoconstrictive mechanism.

Data of children with AC (group AC, n = 49) and conventionally programmed devices (group Conv, n = 41) were analysed. A total of 1106 outpatient visits and 147 Holter recordings were screened for device reprogramming and invasive re-intervention. At 2 and 5 years, freedom from reprogramming differed significantly between groups (AC: 63/35% vs. Conv: 13/4%; P < 0.0001), whereas freedom from re-intervention was not different (AC: 95/90% vs. Conv: 95/85%; P = 0.26). Mean yearly rate of reprogramming was lower in group AC (AC: 0.67 ± 0.55 vs. Conv: 1.13 ± 0.82; P = 0.005). Follow-up duration correlated with a decreasing number of reprogramming per year in group Conv ( = –0.73, P < 0.001). No ventricular output reprogramming was required in group AC. Holter recordings required 0.07 ± 0.13 reprogramming per year in group Conv, none in group AC (P < 0.001). Holter-detected lead dysfunction prompted re-intervention in one patient of each group.

Estimated freedom from as well as total yearly rate of device reprogramming was favourable for AC-programmed devices. No difference was seen for the incidence of invasive re-interventions. AC ventricular output control was effective. Structured device follow-up and Holter recordings in specific patient groups remain mandatory for all devices in paediatric patients.

At first evaluation, one female had an aborted sudden cardiac death and eight patients suffered from recurrent syncopes. Intrathoracic cardioverter defibrillator (ICD) implantation was done in the patient with aborted sudden cardiac death and in six patients with recurrent syncopes. One of these six patients had intermittant 2–3° AV block. Another patient had inducible ventricular tachycardia (VT) at electrophysiological study. Follow-up over more than 3 years in all but one patient was characterized by documented monomorphic VT in the patient with inducible VT and ICD implantation (6%). The patient with aborted sudden cardiac death had only non-sustained VT’s shortly after ICD implantation. From the eight patients without syncopes two more patients developed AV block and SA block 3° (18%). Lead-associated complications appeared in three of eight patients with ICDs (38%). Repeated ajmaline challenge was positive in four of eight cases (50%). One patient had a new mutation encoding for SCN5A gene.

Ajmaline challenge in typical ARVC characterizes a subgroup of elderly, predominantly female patients with the risk of developing conduction disease. Tachycardia-related events are rare. The indication of ICD implantation in recurrent syncopes is critical as the rate of lead-associated complications in a more than 3 years follow-up is high.

Sixteen haemodialysis (HD) patients underwent a 24 h Holter recording before and during HD sessions with six randomized combinations of electrolytes concentrations of the dialysis bath (K⁺, 2 and 3 mmol/L; Ca²⁺, 1.25, 1.5, and 1.75 mmol/L). The effect of different dialysis baths on QT interval was significant (P < 0.05). The longest mean QTc was observed with the lowest K⁺ (2 mmol/L) and Ca²⁺ concentrations (1.25 mmol/L), whereas the shortest mean QTc was observed with the highest K⁺ (3 mmol/L) and Ca²⁺ concentrations (1.75 mmol/L). QTc was >440 ms in 9 of 16 patients (56%) at the lowest Ca²⁺ and K⁺ concentrations, and in 3 of 16 patients (18%) at the highest electrolytes level. Changes in QTc during the HD sessions were inversely correlated with that in total Ca and Ca²⁺ plasma concentrations (P < 0.0001).

Changes in ventricular repolarization duration associated with HD largely depend on the concentrations of Ca²⁺ and K⁺ in the dialysis bath. These findings may have important implications for the choice of the electrolytes concentration of the dialysis bath during the HD session.

Patients diagnosed with Brugada ECG pattern were enrolled in the study. Four standard cardiac autonomic function tests were performed. The presence of ≥2 abnormal test results were considered definite evidence for the presence of CAN. Types 1, 2, and 3 Brugada ECG pattern were found in 28, 56, and 31 patients, respectively. CAN was detected in 13 (46%) patients with type 1 Brugada ECG pattern. In contrast, none of the type 2 or 3 Brugada patients had CAN. Of 13 patients with CAN, 11 had previous history of cardiac events (84%), whereas only 2 of 15 patients without CAN had history of previous cardiac events (13%; P = 0.01). The most noteworthy finding was that all of the type 1 Brugada patients with CAN were male (CAN was not detected in females).

It was concluded that CAN is an important risk indicator in BS. CAN is more common in men. Male gender, per se, is not an independent risk factor for development of ventricular arrhythmia but also CAN, which is an important risk factor in BS, is more common in men; therefore men are susceptible to the development of cardiac events.