Intravenous isosorbide dinitrate in patients with refractory pump failure and acute myocardial infarction.

We studied the hemodynamic effects of isosorbide dinitrate administered by continuous i.v. infusion to 22 patients with chronic refractory pump failure and 18 with pump failure due to acute myocardial infarction. In patients with severe pump failure, i.v. ISDN markedly decreased pulmonary capillary wedge pressure (p less than 0.001), moderately increased cardiac output (p less than 0.01), and decreased systemic vascular resistance (SVR) (p less than 0.001). There were no deleterious effects on arterial pressure and heart rate. The effects obtained in acute and chronic left ventricular failure were similar. Patients with initial SVR levels lower than 1500 dyn-sec-cm-5 did not significantly increase their cardiac output (p less than 0.005). Cardiac output increased more than 25% only in patients with initial high SVR levels (greater than 2000 dyn-sec-cm(-)5). Positive correlations were found between high SVR and elevated plasma catecholamines (r = 0.53, p less than 0.05) and between the initial SVR and initial heart rate (r = 0.70, p less than 0.01). The i.v. administration of isosorbide dinitrate appears to be an efficient therapy, particularly in selected patients with ischemic pump failure.