A comparison of the haemodynamic effect of isosorbide-5-mononitrate and isosorbide dinitrate administered in intravenous injection to patients with acute myocardial infarction.

The haemodynamic effects of 10 mg of isosorbide-5-mononitrate (IS-5-MN) and 10 mg of isosorbide dinitrate (ISDN), administered in intravenous injection, were compared in 16 patients with acute myocardial infarction. The study, using the balloon thermodilution catheter, took 4 hours to complete. Both drugs produced a decrease in pulmonary and peripheral arterial pressure, cardiac index, stroke and stroke work indexes; the effect was present immediately after administration to reach a maximum 3-15 minutes later, after which the values gradually returned to baseline levels. While IS-5-MN resulted in an increase in peripheral arterial resistance, heart rate rose briefly following the administration of ISDN. After IS-5-MN, pulmonary diastolic pressure decreased by 15% and peripheral arterial pressure by 5%, and stroke work index by 12%; the magnitude of decrease was double following the administration of ISDN (30%, 15% and 23%, respectively). The decrease in cardiac and stroke indexes was likewise less pronounced after IS-5-MN than after ISDN, the difference, however, was not statistically significant. Duration of the haemodynamic effect of both drugs was about the same--approximately 3 hours.