[Hemodynamic effects of nitroglycerin in acute myocardial infarct]

The influence of sublingual dose (0.5 mg) of nitroglycerin on the cardiac function and central haemodynamics was studied in 53 patients with acute myocardial infarction in the first hours of illness. The cardiac output was measured by radiocardiography and tetrapolar rheography, filling pressure on the left ventricle by catheterization of the pulmonary artery. It is shown that nitroglycerin leads to decrease of the systemic arterial pressure and filling pressure in the left ventricle. In patients with a hyperkinetic type of circulation there is a decrease of cardiac output caused by predominantly decreased venous return of the blood. In patients with eukinetic and especially with a hypokinetic type of haemodynamics nitroglycerin leads to significant increase of the cardiac output, caused by predominant decrease of after-load. It is concluded that nitroglycerin is indicated in any haemodynamic variant of myocardial infarction (except cases of marked arterial hypotension). It improves the pumping function of the heart and ensures its oxygen supply.