Comparison of intravenous flecainide, propafenone, and amiodarone for conversion of acute atrial fibrillation to sinus rhythm

In a prospective, single-blind trial, we randomized 150 consecutive symptom atic patients with acute (less than or equal to 48 hours' duration) atrial fibrillation to receive intravenous flecainide, propafenone, or amiodarone. Flecainide and propafenone were administered as a bolus dose of 2 mg/kg in 20 minutes. A second bolus dose of 1 mg/kg in 20 minutes was administered if conversion to sinus rhythm was not achieved after 8 hours. Amiodarone wa s administered as a bolus of 5 mg/kg in 20 minutes followed by a continuous infusion of 50 mg/hour. By the end of a 12-hour observation period, conver sion to sines rhythm was achieved in 45 patients (90%) in the flecainide gr oup, 36 (72%) in the propafenone group, and 32 (64%) in the amiodarone grou p (p = 0.008 for the overall comparison, p = 0.002 for flecainide vs amioda rone, p = 0.022 for flecainide vs propafenone, and p 0.39 for propafenone v s amiodarone). When compared with amiodarone, this higher reversion rate wi th flecainide was present from the first hour of the study period. However, only after administering the second bolus was there a significant differen ce between flecainide and propafenone. Median time to conversion to sinus r hythm was different among groups (p <0.001), and it was lower in the flecai nide (25 minutes; range 4 to 660) and propafenone (30 minutes; range 10 to 660) groups than in the amiodarone group (333 minutes; range 15 to 710; p < 0.001 for both comparisons). Flecainide, at the doses administered in this study, is more effective than propafenone and amiodarone for conversion of acute atrial fibrillation to sinus rhythm. Propafenone and amiodarone have similar conversion rates, although propafenone was faster in achieving the conversion to sinus rhythm. (C)2000 by Excerpta Medica, Inc.