[Hemodynamic effect of isosorbide-5-mononitrate in acute cardiac insufficiency secondary to myocardial infarct].

The hemodynamic effects of IS-5-MN were studied in 18 patients with acute myocardial infarction (AMI) complicated with left ventricular failure. Before treatment, 13 patients were in Forrester's hemodynamic class II and 5 in class IV. Hemodynamic monitoring was performed for 3 days, and the following parameters were measured: heart rate (HR), blood pressures (BP), right atrial (RAP), pulmonary artery and pulmonary capillary (PCP) pressures, cardiac index (CI), systemic (SVR) and pulmonary (PVR) vascular resistances, and coronary perfusion pressure (CPP). Patients with clinical symptoms of acute pulmonary edema or systolic BP (BPs) less than 90 mmHg were not included. Twenty mg of 5-IS-MN per os were administered every 8 h. Hemodynamic measurements and IS-5-MN plasma levels were obtained in basal conditions and 1/2, 1, 2, 6 and 8 h after the first and seventh dose of IS-5-MN. A significant decrease of systolic and diastolic BPs, RAP, PCP, SVR and PVR was observed after 1/2 of IS-5-MN administration and was maintained through the study, while CI and CPP increased and HR remained unchanged. The hemodynamic effect was maintained after the seventh dose, with a further decrease of the following parameters: BP, RAC, PCP and PVR. However, 2 patients were withdrawn from the study due to severe symptoms of heart failure. One patient presented headache. IS-5-MN plasma levels were identified after 1/2 h, with a peak level after 1 h, and were similar after the seventh dose. A significant correlation was found between the IS-5-MN levels and the delta RAP and delta PCP after the seventh dose.(ABSTRACT TRUNCATED AT 250 WORDS)