P-08 Amiodarone prophylaxis for ventricular arrhythmias during aortic valve replacement

Abstract

Introduction. Ventricular fibrillation accounts for 20% of the mortality after aortic valve replacement and the second most common cause of death. Several studies have shown reduction in the incidence of atrial fibrillation with prophylactic amioda-rone. This study examines the role of amiodarone prophylaxis for ventricular arrhythmias during aortic valve replacement. Method. Thirty patients were randomly assigned to two groups; patients in the first group received 2.5 mg/kg of amiodarone immediately after induction of anaesthesia and central venous line insertion in the early bypass period, and the other group were control. The number of ventricular arrhythmias (defined as any episode of ventricular fibrillation, haemodynamically unstable ventricular tachycardia, or any ventricular tachycardia lasting more than 30 seconds), number of shocks and total energy for cardioversion, and length of ICU stay were recorded. Results. There were no differences in age, sex, ventricular function, cross-clamp time, or bypass time between the two groups. Four patients in the amiodarone group returned to spontaneous sinus rhythm during separation from cardiopulmonary bypass compared to only 1 patient in the control group. The incidence of ventricular arrhythmias was 73.3% in the amiodarone group and 93.3% in the controls (11 vs. 14 patients, difference 20%), but statistical significance was not achieved (P=0.165). The patients in the amiodarone group responded to fewer cardioversion shocks (P=0.033) and needed less energy (P=0.013. No patients in the amiodarone group experienced any ventricular arrhythmias during the ICU period, while 5 patients in the control group did (P=0.021). Patients in the amiodarone group had an almost statistically significant shorter ICU stay (P=0.05). Discussion. Amiodarone decreased the incidence of ventricular arrhythmias postoperatively and improved the response to car-dioversion. Although a trend was shown, larger studies are needed to establish the role of amiodarone for prevention of ventricular arrhythmias intraoperatively and reduction of ICU length of stay.