Cardioversion with sotalol in selected patients with vagally and adrenergically mediated paroxysmal atrial fibrillation.

This study was designed to evaluate and compare the effects of oral sotalol for the treatment of vagal and adrenergic paroxysmal atrial fibrillation (PAF). Thirty-five eligible patients with atrial fibrillation of >12 hours and <7 days were enrolled in the study. Patients were classified as vagally mediated (group I, n: 14) and adrenergically mediated (group II, n: 21) PAF groups. All patients were given racemic sotalol at a dose up to 120 mg bid for 2 days. At the end of the observation period of 48 hours, 36% of patients (n: five) in group I returned to sinus rhythm. Conversion rate in group II was 71% (n: 15), and this figure was significantly higher than the success rate in group I. Mean times to cardioversion were 22 +/- 15 hours in group I and 16 +/- 14 hours in group II (p < 0.05). The result of this study suggests that oral sotalol is more effective for adrenergic PAF. This beneficial effect of sotalol is not apparent in vagal PAF patients.