© 2001 by European Society of Cardiology
REGULAR ARTICLES
Low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion: results and long-term follow-up
Division of Cardiology, Umberto I° Hospital Mestre, Venice, Italy
AIM: Low-energy internal cardioversion is a new electrical treatment for patients with persistent atrial fibrillation. This paper evaluates the efficacy and safety of low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion, and the clinical outcome of such patients.
METHOD AND RESULTS: The study population consisted of 55 patients [32 male, mean age 65±10 years, 48 (87%) with underlying heart disease] with long-lasting (mean 18±34 months) atrial fibrillation in whom external cardioversion had failed to restore sinus rhythm. Two custom-made catheters were used: one positioned in the right atrium and one in the coronary sinus or the left pulmonary artery. A standard catheter was inserted into the right ventricular apex to provide R wave synchronization. Sinus rhythm was restored in 52 patients (95%) with a mean defibrillating energy of 6.9±2.6 J (320±60 V). No complications were observed. During follow-up (mean 18±9 months), 16 patients (31%) suffered early recurrence (
1 week) of atrial fibrillation and 20 patients (38%) had late recurrence (>1 week, mean 3.5±3.6 months) of atrial fibrillation. Six patients with a late recurrence again underwent cardioversion and five of these maintained sinus rhythm. Therefore, a total of 21/52 patients (40%) were in sinus rhythm at the end of follow-up. No clinical difference was found between patients with and without recurrences.
CONCLUSIONS: Low-energy internal cardioversion is a useful means of restoring sinus rhythm in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion. More than one-third of patients maintained sinus rhythm during long-term follow-up.
Key Words: Atrial fibrillation, low-energy internal cardioversion, external cardioversion, atrial defibrillation, clinical outcome
Correspondence: Dr Gianni Gasparini, Division of Cardiology, Umberto I° Hospital, Via Circonvallazione 50, 30174, Mestre, Venice, Italy. E-mail: cardio.mestre{at}tin.it
[1] Alt E, Schmitt C, Ammer R, et al. Initial experience with intracardiac atrial defibrillation in patients with chronic atrial fibrillation. Pacing Clin Electrophysiol 1994; 17: 1067–1078.[CrossRef][Medline]
[2] Murgatroyd FD, Slade AKB, Sopher SM, Rowland E, Ward DE, Camm AJ. Efficacy and tolerability of transvenous low energy cardioversion of paroxysmal atrial fibrillation in humans. J Am Coll Cardiol 1995; 25: 1347–1353.[Abstract]
[3] Alt E, Ammer R, Schmitt C, et al. A comparison of treatment of atrial fibrillation with low-energy intracardiac cardioversion and conventional external cardioversion. Eur Heart J 1997; 18: 1796–1804.
[4] Lévy S, Ricard P, Lau CP, et al. Multicenter low-energy transvenous atrial defibrillation (XAD) trial results in different subset of atrial fibrillation. J Am Coll Cardiol 1997; 29: 750–755.[Abstract]
[5] Lévy S, Ricard P, Gueunoun M, et al. Low-energy cardioversion of spontaneous atrial fibrillation. Immediate and long-term results. Circulation 1997; 96: 253–259.
[6] Santini M, Pandozi C, Toscano S, et al. Low-energy intracardiac cardioversion of persistent atrial fibrillation. Pacing Clin Electrophysiol 1998; 21: 2641–2650.[CrossRef][Medline]
[7] Boriani G, Biffi M, Pergolini F, Zannoli R, Branzi A, Magnani B. Low-energy internal atrial cardioversion in atrial fibrillation lasting more than a year. Pacing Clin Electrophysiol 1999; 22: 243–246.[CrossRef][Medline]
[8] Sopher SM, Murgatroyd FD, Slade AKB, et al. Low-energy internal cardioversion of atrial fibrillation resistant to transthoracic shocks. Heart 1996; 75: 635–638.
[9] Schmitt C, Alt E, Plewan A, et al. Low-energy intracardiac cardioversion after failed conventional external cardioversion of atrial fibrillation. J Am Coll Cardiol 1996; 28: 994–999.[Abstract]
[10] Taramasco V, Socas A, Ricard P, Lévy S. Internal low-energy cardioversion: A therapeutic option for restoring sinus rhythm in chronic atrial fibrillation after failure of external cardioversion. Europace 1999; 1: 179–182.
[11] Lévy S, Breithardt G, Campbell RWF, et al. Atrial fibrillation: current knowledge and recommendations for management. Eur Heart J 1998; 19: 1294–1320.
[12] Mirowski M, Mower MM, Staewen WS, Tabatznik B, Mendeloff AI. Standby automatic defibrillator: an approach to prevention of sudden coronary death. Arch Intern Med 1970; 126: 158–161.
[13] Mower MM, Mirowski M, Denniston RH. Assessment of various models of acetylcholine-induced atrial fibrillation for study of intra-atrial cardioversion. Clin Res 1972; 20: 388–393.
[14] Nathan AW, Bexton RS, Spurrell RAJ, Camm AJ. Internal transvenous low-energy cardioversion for the treatment of cardiac arrhythmias. Br Heart J 1984; 52: 377–384.
[15] Cooper RAS, Alferness CA, Smith WM, Ideker RE. Internal cardioversion of atrial fibrillation in sheep. Circulation 1993; 87: 1673–1686.
[16] Cooper RAS, Smith WM, Ideker RE. Internal cardioversion of atrial fibrillation: marked reduction in defibrillation threshold with dual current pathways. Circulation 1997; 96: 2693–2700.
[17] Wharton JM and Johnson EE. Catheter based atrial defibrillation. Pacing Clin Electrophysiol 1994; 17: 1058–1066.[CrossRef][Medline]
[18] Lévy S, Lauribe P, Dolla E, et al. A randomized comparison of external and internal cardioversion of chronic atrial fibrillation. Circulation 1992; 86: 1415–1420.
[19] Ayers GM, Alferness CA, Ilina M, et al. Ventricular proarrhythmic effects of ventricular cycle length and shock strength in a sheep model of transvenous atrial defibrillation. Circulation 1994; 89: 413–422.
[20] Wijffels MCEF, Kirchhof CJHJ, Dorland R, Allessie MA. Atrial fibrillation begets atrial fibrillation. A study in awake chronically instrumented goats. Circulation 1995; 92: 1954–1968.
[21] Boriani G, Biffi M, Pergolini F, Branzi A. What is the ideal drug for chronic prophylaxis of atrial fibrillation? In Raviele A (Ed.). Cardiac Arrhythmias 1999 1999; Milan Springer-Verlag 2: pp. 191–195.
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||