COMPARATIVE HEMODYNAMIC-EFFECTS OF TRANSDERMAL VS INTRAVENOUS NITROGLYCERIN IN ACUTE MYOCARDIAL-INFARCTION WITH ELEVATED PULMONARY-ARTERY WEDGE PRESSURE

The comparative haemodynamic effects of transdermal and intravenous nitroglycerin were evaluated in 16 patients with haemodynamic and radiographic left heart failure following a recent myocardial infarction. After the control period patients were randomized to transdermal (10mg(24h)-1) or intravenous (mean dose: 40±9 μg min-1) nitroglycerin. Haemodynamic parameters were recorded after 05, 1, 2, 6, 12, 18 and 24 h during administration of the drug and 2 h after drug discontinuation. After the washout period the alternate system of nitroglycerin administration was adopted, according to a cross-over design. No differences were found in baseline measurements.Transdermal nitroglycerin reduced the pulmonary artery wedge pressure after 0.5h (from 21±5 to 16±5 mmHg; P<0.05). The peak effect occurred at 2 h (12±5 mmHg). The improvement was sustained over 24 h. Transdermal nitroglycerin also significantly reduced mean pulmonary arterial and right atrial pressures (from 28 ±3 to 20 ±5 mmHg and from 6±3 to 2±2 mmHg at peak effect, respectively). Cardiac index increased from 2.5 ± 06 to 2.8 ± 0.81 min-1m-2 (P < 0.05). There was no change in heart rate.Similar haemodynamic changes were observed after the intravenous infusion of nitroglycerin. Thus transdermal nitroglycerin is a safe and effective treatment of acute myocardial infarction with signs of left ventricular failure when an intravenous nitroglycerin infusion cannot be properly implemented. © 1990 The European Society of Cardiology.