Effects of nicardipine on coronary blood flow, left ventricular inotropic state and myocardial metabolism in patients with angina pectoris.

The effects of intravenous nicardipine (2.5 mg) on the left ventricular (LV) inotropic state, LV metabolism, and coronary haemodynamics were analysed in 22 patients with angina pectoris. Measurements were made at fixed heart rate (atrial pacing), under basal state, and during a cold pressor test. After nicardipine, coronary blood flow and oxygen content in the coronary sinus increased significantly. The indices of inotropic state increased slightly, and the rate of isovolumic LV pressure fall improved. Myocardial oxygen consumption was unchanged despite the significant reduction in pressure-rate product, but LV lactate uptake increased, particularly during the cold pressor test. When nicardipine was administered after propranolol, the indices of inotropic state were unaffected. The lack of direct effect of nicardipine on LV inotropic state was further confirmed by intracoronary injection of 0.1 and 0.2 mg in a separate group of 10 patients. It is concluded that the nicardipine-induced coronary dilatation seems to improve perfusion and aerobic metabolism in areas with chronic ischaemia, resulting in reduced lactate production and augmented oxygen consumption.