Amiodarone versus lidocaine and placebo for the prevention of ventricular fibrillation after aortic crossclamping: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: Ventricular fibrillation occurs commonly after aortic crossclamping in patients undergoing cardiac surgery. Ventricular fibrillation increases myocardial oxygen consumption, and defibrillation may harm the myocardium. Thus, a pharmacologic approach to decreasing the incidence of ventricular fibrillation or the number of shocks required may be beneficial. The goal of this study was to evaluate whether amiodarone or lidocaine was superior to placebo for the prevention of ventricular fibrillation after aortic crossclamping in patients undergoing a variety of cardiac surgical procedures.

METHODS: Patients undergoing cardiac surgery requiring aortic crossclamping were randomized to receive lidocaine 1.5 mg/kg, amiodarone 300 mg, or placebo before aortic crossclamp removal The primary outcomes were the incidence of ventricular fibrillation and the number of shocks required to terminate ventricular fibrillation.

RESULTS: A total of 342 patients completed the trial. On multivariate analysis, there was no difference in the incidence of ventricular fibrillation among treatment groups. The number of required shocks was categorized as 0, 1 to 3, and greater than 3. On multivariate analysis, patients receiving amiodarone required fewer shocks to terminate ventricular fibrillation (odds ratio, 0.51; 95% confidence interval, 0.31-0.83; P = .008 vs placebo). There was no difference between lidocaine and placebo in the number of required shocks (odds ratio, 0.86; 95% confidence interval, 0.52-1.41; P = .541).

CONCLUSIONS: In patients undergoing a variety of cardiac surgical procedures, neither amiodarone nor lidocaine reduced the incidence of ventricular fibrillation. Amiodarone decreased the number of shocks required to terminate ventricular fibrillation.