Intracoronary infusion of small doses of nifedipine lowers regional myocardial O2-consumption without altering regional myocardial function.

Intracoronary infusion of low doses (0.1-0.3 microgram X kg-1) of nifedipine caused dose-dependent decreases in regional myocardial O2-consumption, without significant changes in any of its major global hemodynamic determinants: heart rate, left ventricular systolic and end-diastolic pressure and maxLVdP/dt. Furthermore, regional myocardial function was unaltered. It is suggested that nifedipine decreased myocardial O2-consumption by a direct effect on myocardial metabolism. Some of the possible mechanisms involved are discussed.