Single oral loading dose of propafenone for pharmacological cardioversion of recent-onset atrial fibrillation

The efficacy and safety of the single dose oral loading regimen of propafen one for pharmacological cardioversion of recent-onset atrial fibrillation ( AFib) was evaluated by analyzing the trials on the subject identified throu gh a comprehensive literature search. Most of the trials used a single dose of 600 mg for oral loading. The success rates ranged form 56% to 83%, depe nding on the duration of AFib and follow-up after drug administration. The conversion time ranged from 110 +/- 59 to 287 +/- 352 min, depending on the duration of observation after drug administration. The single dose oral lo ading regimen of propafenone was significantly more efficacious than placeb o in the first 8 h after administration but not at 24 h. Compared with the intravenous regimen, the oral regimen resulted in fewer conversions in the first 2 h, but both regimens were equally efficacious afterward. The oral p ropafenone regimen was as efficacious as the single dose oral loading regim en of flecainide but was superior to those of quinidine and amiodarone. The adverse effects reported were transient arrhythmia, reversible QRS-complex widening, transient hypotension and mild noncardiac side effects. The tran sient arrhythmias were chiefly at the time of conversion and included appea rance of atrial flutter, bradycardia, pauses and junctional rhythm. No life -threatening proarrhythmic adverse effects were reported. The single oral l oading dose of propafenone appears to be highly effective for conversion of recent-onset AFib, with a relatively rapid effect within 2 to 3 h and free dom from serious adverse effects. (C) 2001 by the American College of Cardi ology.