Abstract: ObjectiveTo investigate the effects of imidapril on the transmural dispersion of repolarization of the noninfarcted myocardium of rabbits after myocardial infarction. MethodsRabbits with left coronary artery ligation were prepared and allowed to recover for 8 weeks. Monophasic action potentials of three layers myocardium in the noninfarcted myocardium in vivo were recorded. Myocytes were isolated from subendocardial, midmyocardial and subepicardial regions of the noninfarcted left ventricular wall and action potentials were recorded using whole-cell patch clamp technique. ResultsCompared with sham group, the monophasic action potential duration (MAPD₉₀) of three layers myocardium were all prolonged. Prolongation of MAPD_ 90 of midmyocardial cell was the most striking and ventricular fibrillation threshold (VFT) was decreased. After treatment with imidapril, the transmural dispersion of repolarization (TDR) decreased and the VFT enhanced. ConclusionImidapril reduced the transmural dispersion of repolarization of noninfarcted area in rabbits after myocardial infarction, which may contribute to its antiarrhythmic efficacy.

Key words: imidapril, myocardial infarction, action potentials, transmural dispersion of repolarization, rabbits