Placebo-controlled evaluations of propafenone for atrial tachyarrhythmias.

This review summarizes the results of placebo-controlled trials of propafenone, a class IC antiarrhythmic drug, in patients with supraventricular tachycardia, atrial fibrillation (AF), and atrial flutter. Success rates for cardioversion from AF or flutter to sinus rhythm of 9-93% have been obtained with intravenous propafenone. The duration of arrhythmia is an important factor in the degree of success. The use of a single oral dose has also been reported to be effective in a number of studies. Several placebo-controlled studies have confirmed the effectiveness of propafenone in the long-term suppression of both suproventricular tachycardia and AF and flutter. These reported trials have shown consistent benefit with propafenone compared with placebo in preventing arrhythmia recurrence. The adverse side effect profile for propafenone has also been reviewed with particular reference to the potential for proarrhythmia. The rate of side effects is dose-dependent and tends to be higher in patients with underlying structural heart disease. Overall propafenone has been shown to be an effective antiarrhythmic drug with an acceptable side effect profile for the acute and long-term treatment of supraventricular arrhythmias.