ORAL PROPAFENONE FOR RAPID CONVERSION OF RECENT-ONSET ATRIAL-FIBRILLATION - A REVIEW

OBJECTIVE: To review comparative studies evaluating oral propafenone f or restoring sinus rhythm in recent onset. atrial fibrillation. DATA S OURCES: A MEDLINE search of the English-language literature (1966 to 1 996) along with any referenced articles not identified by MEDLINE. STU DY SELECTION: Because intravenous propafenone is not marketed in Canad a, only studies evaluating oral propafenone were included. Studies wer e selected if they compared oral propafenone with placebo or other ant iarrhythmic agents for converting recent onset atrial fibrillation to normal sinus rhythm. DATA SYNTHESIS: Propafenone is often used as a fi rst-line agent for pharmacological cardioversion of atrial fibrillatio n. In earlier studies, the efficacy of propafenone in restoring sinus rhythm was reported to be low with conversion rates of 6% to 62%. Many of these studies were noncomparative and often included patients with refractory, chronic atrial fibrillation or employed suboptimal doses of propafenone. More recently propafenone has been evaluated in the tr eatment of recent onset atrial fibrillation by using a single 600 mg o ral loading dose. Success rates of 76% at 8 h and 83% at 12 h followin g the loading dose are reported. The incidence of atrial flutter durin g active treatment was similar to that with placebo, with the majority exhibiting 2:1 or greater atrioventricular conduction ratios and hear t rates 150 beats/min or less. CONCLUSIONS: A single 600 mg oral dose of propafenone is highly effective at restoring sinus rhythm in patien ts with acute onset atrial fibrillation with few adverse effects. The small studies reviewed cannot lead to definitive conclusions about the safety of propafenone without prior administration of agents for rate control.