Comparison of oral loading dose of propafenone and amiodarone for converting recent-onset atrial fibrillation

Abstract

In patients with recent-onset atrial fibrillation (AF), restoration of sinus rhythm is considered to be the first-line therapeutic option. Although this conversion might be obtained by direct-current shock or intravenous antiarrhythmic drugs, administration of an oral loading dose of class I or III antiarrhythmic drugs is more simple and convenient. This prospective, randomized, multicenter study compares the time to conversion to sinus rhythm obtained with an oral loading dose of propafenone or amiodarone. Patients with recent-onset AF (<2 weeks), without contraindications for the 2 drugs, were randomly assigned to be treated with propafenone (600 mg for the first 24 hours and if necessary a repeated dose of 300 mg for 24 hours) or amiodarone (30 mg/kg for the first 24 hours and if necessary a repeated dose of 15 mg/kg for 24 hours). Exact conversion time during the first 24 hours was determined by Holter monitoring. In each treatment group 43 patients with the same baseline characteristics were included. The median time for restoration of sinus rhythm was shorter (p = 0.05) in the propafenone (2.4 hours) than in the amiodarone (6.9 hours) group. After 24 hours (56% in the propofenone and 47% in the amiodarone group) and 48 hours, the same proportion of patients in the 2 groups recovered sinus rhythm (no serious adverse events were noticed). Thus, oral loading dose of propafenone or amiodarone was safe with a similar conversion rate of recent-onset AF. Propafenone had a faster action.