Intravenous Amiodarone in the Management of Atrial Fibrillation

BACKGROUND: Although approved only for therapy of life-threatening ventricular tachyarrhythmias, intravenous amiodarone is also being used for the treatment of atrial fibrillation (AF), generally in the intensive care unit setting and most often after cardiac surgery. When used for AF, dosing regimens and clinical experience have varied. METHODS AND RESULTS: This article summarizes representative reports in hopes of clarifying the role of intravenous amiodarone for practitioners who prescribe it for the management of AF. The most immediate and most predictable response is reduction of the ventricular rate, which generally is noted after the first 300-400 mg. Restoration of sinus rhythm (cardioversion) may occur, but the precise incidence in a placebo-controlled, blinded study has not been determined. When present, it often takes 24 hours, and a total dose of 1,000 mg or more. Least certain is the efficacy of the drug in preventing the appearance (when used prophylactically) or reappearance of AF. CONCLUSIONS: More data are required with regard to patient characterization, electrical system status, and dosing regimen to better characterize intravenous amiodarone for this role.