PROPAFENONE FOR CONVERSION AND PROPHYLAXIS OF ARTRIAL FIBRILLATION

Pharmacologic therapy is widely used far restoration of sinus rhythm a nd prevention of recurrences of atrial fibrillation, Because concerns have been raised about their potential proarrhythmic effects, therapeu tic regimens should be evaluated by placebo-controlled studies to dete rmine their efficacy and safety, One hundred thirty-six patients with persistent atrial fibrillation were randomized to receive propafenone 2 mg/kg over 30 minutes, followed by oral propafenone 150 mg 3 times d aily or matching placebo, Nonresponders to intravenous therapy underwe nt direct-current cardioversion, Both responders to intravenous therap y and converters to sinus rhythm after direct-current cardioversion we re followed for 6 months in a double-blind oral treatment period of pr opafenone 150 mg 3 times daily or matching placebo, Pharmacologic conv ersion to sinus rhythm was achieved in 29% of the patients taking prop afenone and in 17% of patients taking placebo (p greater than or equal to 0.10). Subsequent direct-current cardioversion in nonresponders wa s equally successful (70%) in bath groups (p greater than or equal to 0.10). The proportion of patients free from recurrent symptomatic arrh ythmia at 6 months was 67% for the propafenone and 35% for the placebo group (p <0.01). Time to atrial fibrillation relapse was more favorab le with propafenone than with placebo (p <0.001). The incidence of dru g-related side effects was 10% in the propafenone group and 14% in the placebo group. Thus, ''slow'' infusion of propafenone seems to be of limited value for terminating atrial fibrillation. Oral propafenone at a law dosage 150 mg 3 times daily is well tolerated and effective in maintaining sinus rhythm for 6 months after pharmacologic or electrica l restoration of sinus rhythm. (C) 1997 by Excerpta Medica, Inc.