[Hemodynamic study during 48 hours of delayed-release isosorbide dinitrate (repeated oral administration) in the acute phase of myocardial infarction complicated by left ventricular insufficiency].

The aim of this study was to evaluate the haemodynamic effects of slow release isosorbide dinitrate (IDN) 40 mg oral preparation over a 48 hour period in patients with acute myocardial infarction complicated by left ventricular failure. Fourteen patients (8 male, 6 female) were treated by repeat dose ISD (8 hourly) and the haemodynamic changes were recorded at 1 hr, 2 hrs, 6 hrs, 12 hrs, 24 hrs, and 48 hrs. After 48 hours treatment the heart rate was unchanged; mean arterial blood pressure fell from 109.5 +/- 5.6 mmHg to 93.5 +/- 6.2 mmHg (-15%) (p less than 0.01). Cardiac index rose from 2.4 +/- 0.57 1/min/m2 to 2.8 +/- 0.65 1/min/m2 (+16%) (NS); diastolic pulmonary artery pressure fell from 22.5 +/- 7.07 mmHg to 13.7 +/- 4.5 mmHg (-39%) (p less than 0.003); systolic pulmonary artery pressure fell from 40.5 +/- 12.2 mmHg to 28.6 +/- 11.6 mmHg (-30%) (NS). Systemic vascular resistance fell from 2 095.2 +/- 63 dynes/s/cm5 to 1 537 +/- 60 dynes/s/cm5 (-22.3%) (NS). Finally, total pulmonary resistance fell from 561.9 +/- 15 dynes/s/cm5 to 301.9 +/- 14.5 dynes/s/cm5 (-47%) (p less than 0.003). The most valuable effect was therefore the reduction in left ventricular filling pressures which was maximal after about 48 hours. Two groups of patients were identified according to the clinical outcome. The patients in Group I (11 cases) were improved by the fall in diastolic pulmonary artery pressure, the rise in cardiac index and the reduction of systemic valvular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)