Efficacy of amiodarone for the termination of persistent atrial fibrillation

The efficacy and safety of amiodarone in the conversion of persistent atria l fibrillation (AF) were investigated in a prospective, randomized, control led study. Of 67 consecutive patients (32 men, mean age 64 +/- 9 years) wit h AF lasting >48 hours, 33 received amiodarone and 34 received placebo. Bas eline clinical characteristics were similar in the 2 groups. Patients rando mized to amiodarone received 300 mg intravenously for 1 hour and then 20 mg /kg for 24 hours. They were also given 600 mg/day orally, divided into 3 do ses, for 1 week and thereafter 400 mg/day for 3 weeks. Patients randomized to placebo received an identical amount of saline IV over 24 hours and then oral placebo for 1 month. Conversion to sinus rhythm was achieved in 16 of the 33 patients (48.5%) who received amiodarone and in none of the 34 pati ents in the placebo group (p <0.001). None of the patients converted to sin us rhythm within the first 3 days. Those who converted had smaller atria th an those who did not (diameter 41.9 +/- 7.2 vs 50.4 +/- 5.7 mm, p <0.001), Sex, age, baseline heart rate, left ventricular ejection fraction, and the duration of AF did not differ significantly between patients who converted and those who did not. No side effects requiring discontinuation of treatme nt were observed in either group. Amiodarone, administered both intravenous ly and orally, appears to be safe and effective in the termination of persi stent AF. Left atrial diameter is the sole independent predictor of convers ion. (C)1999 by Excerpta Medica, Inc.