INTRAVENOUS PROPAFENONE IN PAROXYSMAL ATRIAL-FIBRILLATION - A RANDOMIZED, PLACEBO-CONTROLLED, DOUBLE-BLIND, MULTICENTER CLINICAL-TRIAL

Background: Pharmacological conversion of paroxysmal atrial fibrillati on is frequently necessary. The aim of this study was to compare intra venous propafenone, a class Ic antiarrhythmic agent, with placebo in p aroxysmal atrial fibrillation (AF) of recent onset (< 72 h). Patients and methods: We randomly allocated 75 patients, aged 18 to 70 years, w ith paroxysmal AF to receive intravenous propafenone (2 mg/kg in 15 mi n followed by 1 mg/kg in 2 h) or the matching placebo. Patients were f ollowed for 3 h. Exclusion criteria were the presence of one of the fo llowing: clinical heart failure, recent acute myocardial infarction, h ypotension, atrioventricular block, Wolff-Parkinson-White syndrome, or current treatment with antiarrhythmic agents or digitalis. Results: N o sign of heart disease was found in 74.7% of the patients. Echocardio graphically determined left atrium diameter was similar in the two gro ups. Conversion to sinus rhythm occurred in 24 of 41 patients allocate d to propafenone and in 10 of 34 patients allocated to placebo (odds r atio 3.2, 95 % confidence intervals 1.3-7.9; p < 0.01). Mean conversio n time was 34 +/- 29 and 71 +/- 55 min, respectively, for propafenone and placebo. Mean heart rate in nonconverters decreased from 146 to 10 9 beats/min in patients treated with propafenone while it remained vir tually unchanged in those treated with placebo. Only minor side effect s were noted. Conclusions: Intravenous propafenone is an effective the rapeutic option for restoring sinus rhythm in patients with paroxysmal AF of recent onset.