Successful use of intravenous amiodarone for refractory ventricular fibrillation just after releasing aortic cross-clamp

Amiodarone is widely used in Europe and the United States for refractory ventricular fibrillation (VF) in various situations, such as VF after myocardial infarction or out-of-hospital cardiac arrest. We report a case of successful treatment with amiodarone of refractory VF immediately after releasing aortic cross-clamp in cardiac surgery. A 66-year-old man suffering from severe aortic stenosis underwent aortic valve replacement (AVR). General anesthesia was induced with propofol and remifentanil, and subsequently AVR was performed under cardiopulmonary bypass. Just after releasing aortic cross-clamp, VF occurred, and it continued despite multiple trials of cardioversion with direct current (DC) shocks of 20 J or 30 J. Furthermore, some DC shocks of 30 J or 50 J after administering lidocaine 60 mg and 0.5 mol·l^-1 magnesium sulfate 20 ml were also ineffective. Then, nifekalant 20 mg was administered and DC shocks of 50 J were repeated intermittently, but VF still persisted. Eventually, VF disappeared after a final DC shock of 50 J with intravenous amiodarone 125 mg. Overall duration of VF was 60 minutes. The patient's trachea was extubated three days after the surgery without any complications. Intravenous amiodarone may be one of the most useful remedies for some types of arrhythmias including persistent VF.