Efficacy and safety of intravenous amiodarone in recent-onset atrial fibrillation: experience in patients admitted to a general internal medicine department.

We examined the efficacy and safety of intravenous amiodarone in 20 unselected patients with recent-onset atrial fibrillation who were admitted to a general internal medicine department during a 6-month period. The treatment protocol included a loading dose of 1200 mg intravenous amiodarone in 24 hours, after which amiodarone treatment was continued orally. Eleven of the 20 patients (55%) converted to sinus rhythm within 48 hours of intravenous amiodarone treatment and were discharged in sinus rhythm, while 9/20 (45%) patients failed to convert during hospitalisation. Six patients (30%) failed to convert to sinus rhythm even after one further month of oral treatment. There was one death and a high frequency (25%) of thrombophlebitis during hospitalisation. The in-hospital non-convertors had a significantly lower ejection fraction and initial low ventricular response rate than the convertors. In conclusion, the acute conversion rate by intravenous amiodarone was at best modest. It is suggested that intravenous amiodarone is probably more effective in patients with rapid recent-onset atrial fibrillation and good left ventricular function.