ASSA13-02-9 The Different Anti-Arrhythmic Effects Between Dronedarone and Amiodarone

Objective This study was devoted to the evaluation anti-arrhythmic effects of dronedarone and amiodarone in an acute pacing–induced in vivo model of ventricular fibrillation (VF) in guinea pigs. Methods Eight guinea pigs were randomised either amiodarone or dronedarone group. Short episodes of VF were induced every 2 minutes by open-chest burst pacing of the right ventricular outflow tract for 15 seconds, and the pacing was performed at twice the pacing threshold with a stimulus duration width of 2 milliseconds. ECG was used to record VF duration before and after dronedarone and amiodarone treatment. Results Compared with before treatment, dronedarone (0.5mg/kg, iv) obviously decreased the durations of VF by 72% after 30 min of injection, and 3(75%) cases in dronedarone group reversing the VF to ventricular tachycardia (VT). Amiodarone (2.5mg/kg, iv) only decreased the durations of VF by 34.6% after 30 min, on case in this group reversing the VF to VT. However, amiodarone increased pacing threshold by 1.94 ± 0.56 times, while dronedarone just increased by 1.14 ± 0.08 times. The difference between the two groups was significantly (P < 0.05). Conclusions Dronedarone and amiodarone are anti-arrhythmic agents with different potency. The administration of dronedarone resulted in a significant reduction the durations of VF, but amiodarone affect the threshold which induced VF.