Patients with infrequent, relatively well-tolerated atrial fibrillation (AF) might not warrant prophylactic antiarrhythmic drug therapy or catheter ablation, but they often require emergency attention for symptomatic episodes. To test outpatient single-dose antiarrhythmic drug use for terminating acute episodes, researchers in Italy studied patients who presented to the emergency department with hemodynamically well-tolerated recent-onset AF. Patients with structural heart disease, conduction-system disease, or major noncardiac comorbidities were excluded, leaving 268 patients who were given single oral doses of flecainide or propafenone and were monitored for at least 8 hours. Fifty-eight patients then were excluded for side effects or lack of efficacy, and the remaining 210 were instructed on outpatient use of the antiarrhythmic agent.

During a mean follow-up of 15 months, 165 patients experienced 618 arrhythmic episodes; during 92% of these, patients treated themselves with single doses of the antiarrhythmic drug at an average of 36 minutes after symptom onset. Palpitations stopped in 94% of episodes after an average of 113 minutes. The drug was effective in terminating all arrhythmic episodes in 84% of patients, and monthly ED visits and hospitalizations were significantly less common after enrollment than during the previous year. Twelve patients had adverse effects, including 1 episode of rapid atrial flutter.

Comment: Electrophysiologists have long been aware that flecainide and propafenone can convert acute episodes of atrial fibrillation, but this is one of the first large evaluations in outpatients. Nevertheless, only practitioners who are thoroughly familiar with the use of these agents should prescribe them, and careful screening for underlying heart disease is imperative.

— Kirsten E. Fleischmann, MD, MPH

Published in Journal Watch General Medicine January 11, 2005