Oral flecainide for prophylaxis of paroxysmal atrial fibrillation.

This study was designed to assess the clinical efficacy of oral flecainide for the prevention of paroxysmal attacks of atrial fibrillation (AF). Forty patients with frequent, very symptomatic AF were selected for study; 31 had vagally induced AF. All patients were considered to be drug resistant. Each had recurrences of AF despite previous antiarrhythmic therapy that included high doses of amiodarone given alone or in combination with a class IA antiarrhythmic agent. In 6 patients, very high doses of amiodarone were efficacious in the prevention of AF; however, the doses had to be reduced because of adverse effects, which resulted in the recurrence of the arrhythmia. Patients were followed up for a period of 18 months and assessed by both symptom development and Holter monitor recordings. Patients received flecainide at an initial dose of 300 mg/day, which was increased to 400 mg/day in case of failure. If the initial dose was successful, the dose was reduced until the lowest one required to prevent recurrences of the arrhythmia was found. Amiodarone was also reduced or withdrawn whenever possible. The results show that AF in 32 of 40 patients was controlled with flecainide given alone (11 of 32) or in combination with amiodarone (21 of 32). Only 8 patients were considered to be drug resistant. The mean dose required to prevent recurrences of AF was also determined for each drug. The combined administration of flecainide and amiodarone allowed a significant reduction in the daily dose of amiodarone (p less than 0.005). On the other hand, daily doses of flecainide given with or without amiodarone were not significantly different (204 vs 209 mg/day).(ABSTRACT TRUNCATED AT 250 WORDS)