| Abstract | uIntroductionvArrhythmias occurring on myocardial ischemia are common among cardiac patients and have been good targets for pharmacological and other antiarrhythmic treatments. Such arrhythmias often occur suddenly and become very serious transforming into ventricular fibrillation (VF). We have been studying the efficacy of various antiarrhythmic drugs on ventricular arrhythmias occurring in the chronic phase of canine myocardial infarction, i.e. two-stage coronary ligation arrhythmia1,2). Class I, II, III and IV antiarrhythmic drugs and also coronary vasodilators and positive inotropic agents were examined. In those studies, the antiarrhythmic plasma concentration data were obtained. Plasma concentrations which produced 50% reduction of the control arrhythmias, IC50, were used for quantitative comparison of the potencies of antiarrhythmic drugs. Also we have started experiments using ventricular arrhythmias occurring in the acute phase of myocardial ischemia, occurring during ischemia, and those occurring on reperfusion in dogs using several class III agents3,4). |
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