The present article briefly reviews the processes underlying excitation-contraction coupling in cardiomyocytes and vascular smooth muscle cells, their perturbations during reversible and irreversible myocardial ischemia and reperfusion, notably the pathogenetic role of increased intracellular calcium concentrations, and finally the beneficial effects of calcium antagonists on the impairment of coronary vasomotor tone, on cardiac contractile dysfunction and on myocardial infarction.