Cardioversion of AF following catheter ablation
BALTIMORE, MARYLAND. The recurrence of afib or flutter following a pulmonary vein ablation (PVI) procedure is not uncommon, especially during the 3 months post-procedure. If the recurring arrhythmia does not terminate spontaneously, then electrical cardioversion is used. Now a team of electrophysiologists from the Johns Hopkins Hospital report their experience with cardioversion of post-procedural persistent AF and atrial flutter.

Their study included 55 patients (85% male, average age of 58 years, 15% with coronary artery disease) who underwent catheter ablation for AF and subsequently required electrical cardioversion for persistent AF (45 patients or atrial flutter (10 patients). Thirty-five percent of patients had paroxysmal afib, 18% had persistent afib, and 47% were in permanent AF (long-standing persistent). All patients underwent a pulmonary vein isolation procedure using a wide area circumferential approach guided by electroanatomical (CARTO) mapping (Pappone protocol). Isolation of the pulmonary veins was the procedural end-point.

The study participants were followed for an average of 15 months. During the first 3 months (blanking period), 43 patients underwent cardioversion with 16% having complete success (no afib, no drugs), 21% having partial success (a 90% or better reduction in afib burden with or without the use of previously ineffective antiarrhythmic drugs), and the remaining 63% were classified as failures. Patients who underwent late cardioversion (beyond 90 days from procedure) had a complete success rate of 8%, a partial success rate of 17%, and a failure rate of 75%.

At the end of the 15-month follow-up, 15% were in normal sinus rhythm (complete success), while 20% had a partial success, and 65% had a failed outcome. The researchers conclude that more than 80% of patients who undergo cardioversion for persistent AF or atrial flutter following a PVI experience recurrence.

Chilukuri, K, et al. Outcomes in patients requiring cardioversion following catheter ablation of atrial fibrillation. Journal of Cardiovascular Electrophysiology, Vol. 21, January 2010, pp. 27-32

Editor's comment: This study clearly shows that a failed ablation is a failed ablation and that trying to restore sinus rhythm with cardioversion does not alter this fact. What amazes me is that the Johns Hopkins team must have assumed that a simple circumferential PVI performed with electroanatomical guidance would be sufficient to cure persistent and permanent afib. The relevant medical literature abounds with examples that this is definitely not likely to work. Prof. Haissaguerre and colleagues in Bordeaux have demonstrated that permanent afib can indeed be successfully treated, but that it takes a very complicated and extensive approach to achieve this. In a study reported in 2005, the Bordeaux group found that only 5% of patients with persistent or permanent afib achieved full success with a PVI alone. Other steps necessary to achieve return to NSR involved isolation of the superior vena cava and the coronary sinus (thoracic veins), ablation of areas in the left atrium showing unusual electrical activity, and finally, linear ablation involving the cavotricuspid isthmus and the left atrial roof. Altogether 87% of patients were returned to normal sinus rhythm after undergoing one or more of these steps.[1,2,3]

[1] Haissaguerre, M, et al. Catheter ablation of long-lasting persistent atrial fibrillation: Critical structures for termination. Journal of Cardiovascular Electrophysiology, Vol. 16, November 2005, pp. 1125-37
[2] Haissaguerre, M, et al. Catheter ablation of long-lasting persistent atrial fibrillation: Clinical outcome and mechanisms of subsequent arrhythmias. Journal of Cardiovascular Electrophysiology, Vol. 16, November 2005, pp. 1138-47
[3] Tse, Hung-Fat and Lau, Chu-Pak. Catheter ablation for persistent atrial fibrillation: Are we ready for "prime time"? Journal of Cardiovascular Electrophysiology, Vol. 16, November 2005, pp. 1148-49