Prevalence, predictors, and prognosis of atrial fibrillation early after pulmonary vein isolation: findings from 3 months of continuous automatic ECG loop recordings.

INTRODUCTION: Following pulmonary vein isolation (PVI) for atrial fibrillation (AF), early recurrences are frequent, benign and classified as a part of a "blanking period." This study characterizes early recurrences and determines implications of early AF following PVI. METHODS AND
RESULTS: Seventy-two consecutive patients (59.8 +/- 10.7 years, 69% male) were studied following PVI for paroxysmal or persistent AF. Subjects were fitted with an external loop recorder for automatic, continuous detection of AF recurrence for 3 months. AF prevalence was highest 2 weeks after PVI (54%) and declined to an eventual low of 22%. A significant number (488, 34%) of recurrences were asymptomatic; however, all patients with > or =1 AF event had > or =1 symptomatic event. No clear predictor of early recurrence was identified. Forty-seven (65%) patients had at least 1 AF episode, predominantly (39 of 47 patients, 83%) within 2 weeks of PVI. Of the 33 patients who did not experience AF within the first 2 weeks, 85% (28/33) were complete responders (P = 0.03) at 12 months. Recurrence at any time within 3 months was not associated with procedural success or failure.
CONCLUSIONS: Early AF recurrence peaks within the first few weeks after PVI, but continues at a lower level until the completion of monitoring. A blanking period of 3 months is justified to identify patients with AF recurrences that do not portend procedure failure. Freedom from AF in the first 2 weeks following ablation significantly predicts long-term AF freedom.