Long‐term Efficacy of Flecainide in Paroxysmal Atrial Fibrillation

. The efficacy and safety of flecainide for long-term prevention of paroxysmal atrial fibrillation (AF) were studied in an open trial. Twenty patients with very frequent attacks (mean 13 per month) of paroxysmal AF for many years (mean 8 years) participated. Before inclusion, the patients had unsuccessfully been treated with an average of 3.3 antiarrhythmic drugs. Efficacy was jugded from a carefully kept diary in which the patients made daily notes of any AF attacks and possible side-effects from 1 month before treatment until the end of a follow-up period of 6 months. Twelve patients (60%) were completely free from AF and 11 of these are still successfully treated with flecainide after 11–38 months (mean 24 months). Flecainide plasma levels did not differ between responders and non-responders. Eleven patients (55%) had adverse effects but these were usually mild and well tolerated, necessitating withdrawal or dose reduction resulting in relapse of AF only in three patients (15%). No proarrhythmic events were seen.