Abstract:OBJECTIVE: To study the anti-arrhythmic efficacy of ginsenoside Re (GSRe) and its protective effects against myocardial injuries in rabbits with isoproterenol-induced triggered ventricular arrhythmia (TVA). METHODS: TVA model was prepared by intravenous injections of isoproterenol at a constant speed of 5 mg/kg/min. When TVA appeared, rabbits were randomly injected with GSRe (5, 10 or 20 mg/kg), verapamil (0.4 mg/kg) or placebo. The duration of maintaining sinus rhythm was observed. Meanwhile, isoproterenol was continued to be injected at a constant speed of 5 mg/kg/min. After 1 hr of isoproterenol injection, the rabbits were sacrificed. Cardiac muscles in the cuspidate position of the left ventricle were sampled for optical microscopy and electron microscopy. RESULTS: GSRe and verapamil treatment restored sinus rhythm. The duration of sinus rhythm was 177.00±5.66 s within 3 minutes in the verapamil treatment group and was 177.83±5.31, 21.00±2.83 and 4.50±1.64 s, respectively, in the 20, 10 and 5 mg/kg GSRe treatment groups. Histopathologic examination demonstrated that GSRe treatment (20 and 10 mg/kg) alleviated myocardial injuries induced by TVA. CONCLUSIONS: GSRe has anti-arrhythmic efficacies and protective effects against myocardial injuries in rabbits with TVA. It may therefore be a possible therapy for TVA.[Chin J Contemp Pediatr, 2009, 11 (5):384-388]