Abstract: An ishemic ventricular tachyarrhythmias canine model was established in open-chest dogs subjected to programmed electrical stimulation (PES)for 5-8 days after acute myocardial infarction. The electrophysiologic effects of neferine (Nef) and procainamide (PA) were observed in this model. With routine methods of PES,ventricular tachycardia (VT)and ventricular fibrillation (VF) could be reproducibly initiated. Both drugs lengthened the QTc interval (P<0.01) and effective refractory period(ERP)of normal and ischemic ventricular myocardia (NERP and IERP) respectively (P<0.01), decreased the dispersion of ERP in ischemic myocardium and the dispersion of ERP in left ventricle (P<0.01), and increased the diastolic excitability threshold of normal and ischemic ventricular myocardia (P<0.01). The two compounds prevented the PES-induced VT or VF (Nef group P<0.01, PA group P<0.05) and ischemia-induced VF (P<0.05). The results indicated that neferine and procainamide may be effective in preventing the onset of reentrant ventricular tachyarrhythmias after myocardial ischemic damage in dogs.

Key words: Neferine, Neferine, Procainamide, Procainamide, Arrhythmia, Arrhythmia, Ischemic, Ischemic, Electrophysiology, Electrophysiology, Myocardial infarction, Myocardial infarction, Canine, Canine