CONVERSION OF RECENT-ONSET ATRIAL-FIBRILLATION TO SINUS RHYTHM USING A SINGLE ORAL LOADING DOSE OF PROPAFENONE - COMPARISON OF 2 REGIMENS

A population of 105 patients with recent onset (<72 h) atrial fibrilla tion was randomly treated with propafenone as a single oral loading do se of 450 mg (Regimen A) or 600 mg (Regimen B) or with placebo. A 24-h Holter was performed. Criteria of efficacy were conversion to sinus r hythm at 2, 4 and 8 h compared to placebo and also significant reducti on of mean ventricular rate in persistent atrial fibrillation. After 2 h, regimen B was more effective than either regimen A (43% vs. 8%; p= 0.001) or placebo (11%; p=0.004). At 4 h, both the active treatments w ere more effective than placebo (17% vs. 46% regimen A and 57% vs. reg imen B; p<0.04 and p<0.001, respectively). Sinus rhythm resumed within 24 h in 71%, 80% and 69% of the patients with regimen A, B and placeb o, respectively (p=not significant): The mean ventricular rate reducti on after 1 h was 8%, 11% and 4% for regimen A, B and placebo, respecti vely (p<0.005 vs. regimen B), and 17%, 25% and 6% respectively (p<0.00 1 placebo vs. regimen A and B, p<0.05 regimen B vs. A) at 2 h. No majo r adverse effect occurred. Atrial flutter with 1:1 atrioventricular co nduction ensued only in one case who received placebo. Propafenone acu te oral administration is more effective than placebo in rapidly conve rting recent-onset atrial fibrillation to sinus rhythm and may be the treatment of choice in this setting limiting hospitalization and contr ibuting to improved quality of life. Copyright (C) 1997 Elsevier Scien ce Ireland Ltd.