Efficacy of Long-term Flecainide Therapy in Patients with Paroxysmal Atrial Fibrillation —Analysis Based on Time of Onset—

Abstract

This study sought to evaluate the efficacy of long‐term flecainide therapy in maintaining sinus rhythms in patients with paroxysmal atrial fibrillation (AF. based on time of onset. Flecainide (150 mg/day. was administered as an antiarrhythmic drug to a total of 70 patients (54 men and 16 women: mean age 65 ± 10 years. after sinus rhythm was restored spontaneously or by electrical and/or pharmacological cardioversion. Paroxysmal AF was divided into three categories based on time of onset: diurnal type (N = 11), nocturnal type (N = 13), and mixed type (N = 46). The mean follow‐up period was 37.7 ± 17.7 months. The duration of sinus rhythm maintenance in patients with diurnal and nocturnal paroxysmal AF was 32.4 ± 10.4 months and 20.8 ± 8.3 months, respectively; the duration of sinus rhythm maintenance in those with mixed paroxysmal AF was only 7.2 ± 2.1 months. Significant differences were observed in duration between diurnal and mixed cases (mean ± S.E., P < 0.05). Actuarial recurrence‐free rates at 1, 3, 6, 9 and 12 months were 90.9%, 63.6%, 63.6%, 54.5%, and 54.5%, respectively, for diurnal cases; 84.6%, 76.9%, 53.8%, 38.5%, and 30.8%, respectively, for nocturnal cases; and 58.7%, 39.1%, 28.3%, 21.7%, and 15.2% respectively, for mixed cases. Significant differences in rates at 12 months were observed between diurnal and mixed cases (P < 0.05). These results suggest that flecainide is highly effective in preventing AF recurrence in patients with diurnal paroxysmal AF.