Nitroglycerin ointment in acute myocardial infarction.

The hemodynamic effects of nitroglycerin ointment were studied in 22 patients with acute myocardial infarction. Control measurements were obtained and observations were made over the ensuing 240 minutes. There was no change in heart rate, cardiac index or stroke index. Ninety minutes after application of the ointment, peak decrements were evident in mean arterial pressure (from 100 to 88 mm Hg) (P less than 0.001), pulmonary capillary wedge pressure (from 19 to 13 mm Hg) (P less than 0.001), right atrial pressure (from 8 to 5 mm Hg) (P less than 0.001) and heart X systolic blood pressure (from 1,155 to 1,044 mm Hg/min X 10(-1) (P less than 0.02); significant changes were still present at 240 minutes. Total peripheral resistance decreased maximally from 19.8 to 17.2 units (P less than 0.02); the transmyocardial gradient (arterial diastolic -- pulmonary capillary wedge pressure) did not decrease during the study. These data indicate that nitroglycerin ointment improves cardiac performance in patients with acute myocardial infarction while reducing the determinants of myocardial oxygen consumption and preserving the transmyocardial gradient for coronary blood flow.