Long-term outcome in patients with chronic atrial fibrillation after successful internal cardioversion.

Internal cardioversion is safe and effective in restoring sinus rhythm, even in patients with persistent AF of prolonged duration. Up to 40% to 50% of patients with AF lasting >1 year but <3 years could be maintained in sinus rhythm using a class III antiarrhythmic drug after successful internal cardioversion, and amiodarone appears to be more effective than sotalol in this patient population.