[Intravenous nitroglycerin as vasodilator therapy in acute myocardial infarction (author's transl)].

Thirteen patients with left ventricular failure complicating acute myocardial infarction were treated with intravenous nitroglycerin. The hemodynamic criterium for admission to this study was a pulmonary capillary wedge pressure greater than 15 mm Hg. All patients received intravenous nitroglycerin at infusion rates sufficient to lower pulmonary capillary wedge pressure by an average of 15 mm Hg, corresponding to the optimal left ventricular filling pressure in acute myocardial infarction. During this study, heart rate did not vary significantly; pulmonary capillary wedge pressure decreased from 24 +/- 0,7 to 15 +/- 0,8 mm Hg (p less than 0,001), mean arterial pressure from 95 +/- 5 to 80 +/- 4 mm Hg (p less than 0,005), mean right atrium pressure from 8,7 +/- 1 to 4,6 +/- 0,8 mm Hg (p less than 0,001), systemic vascular resistance index from 36,4 +/- 2 to 29,6 +/- 2 mm Hg/mm-1/l/m2 (p less than 0,005). Cardiac index increased from 2,5 +/- 0,2 to 2,7 +/- 0,1 l/mn/m2 (p less than 0,025) and stroke work index did not vary significantly. These data indicate that nitroglycerin provides a significant improvement of cardiac performance, more through reduction of preload than through reduction of afterload, the later being however significant. This study points out that intravenous nitroglycerin is a most efficient drug in patients with left ventricular failure complicating acute myocardial infarction.