Importance of early cardioversion
ANN ARBOR, MICHIGAN. Early recurrence of atrial arrhythmia (atrial fibrillation or atrial flutter) after a pulmonary vein isolation (PVI) procedure is not uncommon and may be experienced by 30-50% of patients. However, such early recurrence does not necessarily equate to long-term failure of the procedure.

Drs. Fred Morady and Hakan Oral and colleagues at the University of Michigan now report that the prompt use of electrical cardioversion in ablatees who develop persistent arrhythmia (AF or flutter lasting more than 24 hours) following an ablation may help reverse remodeling and materially reduce the need for a follow-up ablation. Their trial included 215 paroxysmal and 169 persistent afibbers who underwent a segmental PVI with additional lesions as required. Among these 384 patients 24% experienced a persistent arrhythmia (80% AF and 20% flutter). The arrhythmia occurred within 24 hours in 6%, within the first week in 37%, within the first month in 66%, and within the first 3 months in 88% of cases. All patients with persistent arrhythmias were treated with electrical cardioversion and in 52% of cases with antiarrhythmic drugs as well. Cardioversion was performed within 1 week in 34% of cases, within 1 month in 49%, and within 3 months in 75%. Sixteen months after the cardioversion 27% of the patients were in normal sinus rhythm without the use of antiarrhythmic drugs.

The University of Michigan researchers made the rather astounding discovery that patients who had been cardioverted within 30 days of their persistent arrhythmia occurring were 22 times more likely to be in sinus rhythm than were those who had been converted later. Put in another way, 50% of patients who had been cardioverted promptly, i.e. within 30 days were in sinus rhythm 16 months later as compared to only 4% in the group whose cardioversion was delayed by more than a month. This association held true for both patients with post-ablation persistent AF and post-ablation atrial flutter.

The researchers suggest that early restoration of sinus rhythm is likely to prevent progressive atrial electroanatomical remodeling and thus facilitate long-term maintenance of sinus rhythm.

Baman, TS, et al. Time to cardioversion of recurrent atrial arrhythmias after catheter ablation of atrial fibrillation and long-term clinical outcome. Journal of Cardiovascular Electrophysiology, 2009 [Epub ahead of print]

Editor's comment: This is clearly an enormously important finding and underscores the need to undergo cardioversion as early as possible if persistent AF or flutter develops after a PVI.