Beneficial effects of dopamine combined with intravenous nitroglycerin on hemodynamics in patients with severe left ventricular failure.

Abstract

Hemodynamic effects of dopamine and i.v. nitroglycerin alone, and in combination, were studied in 27 patients with severe left ventricular failure. Dopamine alone increased cardiac index form 1.8 to 2.5 l/min per m2 but also increased wedge pressure from 24 to 30 mm Hg and heart rate from 88 to 101 beats/min. Arterial O2 saturation fell from 92% to 87% (P < 0.001). Nitroglycerin alone had a lesser effect on cardiac index (1.8 to 2.2 l/min per m2) but decreased wedge pressure from 26 to 16 mm Hg and heart rate from 91 to 86 beats/min. Arterial O2 saturation fell from 91 to 90% (NS [not significant]). Combined dopamine and nitroglycerin administration resulted in optimal hemodynamics, with cardiac index of 2.9 l/min per m2, wedge pressure of 17 mm Hg and heart rate of 96 beats/min. Arterial O2 saturation remained low at 88% in spite of the reduction in left ventricular filling pressure, which probably reflects increased intrapulmonary right-to-left shunting coupled with increased pulmonary blood flow. Evidently, the combination of dopamine with i.v. nitroglycerin should be considered for patients with severe left ventricular dysfunction who require temporary pharmacologic support.