Additional Indexing Words: Exertional angina Cardiac index

Fifteen patients with coronary heart disease and previous myocardial infarction but without exertional angina were studied at rest and during exercise. Te hemodynamic response to exercise varied, being normal in some patients while others showed evidence of marked depression of ventricular performance. Ten patients were restudied after nitroglycerin. During exercise after administration of this drug, ventricular performance was normal in all. The exact mechanism of action of nitroglycerin is uncertain, but it may reduce myocardial oxygen needs through reduction in left ventricular volume or increase in coronary blood flow to ischemic areas or both