[Hemodynamic effects of intravenous isosorbide dinitrate in acute myocardial infarct].

The hemodynamic effects of intravenous isosorbiddinitrate (ISDN) were studied in 15 patients with acute myocardial infarction. Pressure and flow parameters were measured by right heart and radial catheterization and by the thermodilution method. 3-9 mg/hour ISDN was infused intravenously and the hemodynamic values were measured during half an hour in clinically stable state. The statistical analysis was carried out by paired Student's t-test and factors analysis. After ISDN therapy 10 patients showed a significant fall in pulmonary capillary pressure (-24%), 9 a rise in stroke volume index (+21%) and cardiac index (+13%). Two patients only exhibited a rise in pulmonary capillary pressure (+10%) and one a fall in cardiac index (-5%). ISDN changes in pulmonary capillary pressure, stroke volume and cardiac output were mainly due to changes in pulmonary and systemic vascular resistances and much less to those in the systemic venous bed. It can be supposed that intravenous ISDN behaves more like a mixed than a venous vasodilator and can be recommended for acute myocardial infarction patients with high pulmonary capillary pressure and low cardiac output.