[Use of nitroglycerin in acute myocardial infarct complicated by mitral insufficiency]

Thirty-five patients with primary large-focal myocardial infarction (MI) were investigated, with mitral incompetence diagnosed in 19. All patients underwent clinical investigation, including electro-, phono- and echocardiography, and tetrapolar chest rheoplethysmography. Direct measurements of pulmonary arterial pressure were made in 11 patients. The investigations were carried out prior to, and at the peak of nitroglycerin action. It was shown that mitral regurgitation was associated with increased incidence and severity of heart failure during the acute stage of MI. Such patients showed low cardiac and stroke index values, a more marked overstrain of the left atrium and left ventricle, and high pulmonary arterial pressure. Intravenous administration of nitroglycerin improves intracardiac hemodynamics in acute MI, its effect being more pronounced in patients with mitral incompetence. Early and prolonged nitroglycerin treatment is indicated in cases of acute MI with mitral incompetence.