Study objectives: To investigate the efficacy and
safety of amiodarone administered as the drug of first choice in the
conversion of atrial fibrillation, regardless of its duration.
Design: Prospective, randomized, controlled clinical
Setting: Tertiary cardiac referral center.
Patients: Two-hundred eight consecutive patients (102 men;
mean [± SD] age, 65 ± 10 years) with atrial fibrillation.
Interventions: One-hundred eight patients received
amiodarone, and 100 patients received placebo treatment. Patients
randomized to amiodarone received 300 mg IV for 1 h, and then 20
mg/kg for 24 h. They were also given 600 mg/d orally, divided into
three doses, for 1 week, and thereafter 400 mg/d for 3 weeks. Patients
randomized to placebo treatment received an identical amount of saline
solution IV over 24 h, and oral placebo treatment for 1
Measurements and results: Baseline clinical
characteristics were similar in the two groups. Conversion to sinus
rhythm was achieved in 87 of 108 patients (80.05%) who received
amiodarone, and in 40 of 100 patients (40%) in the placebo group
(p < 0.0001). Statistical analysis showed that the duration of the
arrhythmia and the size of the left atrium affected both the likelihood
of conversion to sinus rhythm and the time to conversion in both
groups. No side effects requiring discontinuation of treatment were
observed in either group.
appears to be safe and effective in the termination of atrial
fibrillation. However, extreme cases with a large left atrium and
long-lasting arrhythmia need long-term therapy.