Milrinone, dobutamine, and nitroprusside: comparative effects on hemodynamics and myocardial energetics in patients with severe congestive heart failure.

To assess their comparative effects on hemodynamics and myocardial energetics, we administered nitroprusside (1.5 +/- 0.6 microgram/kg-min), dobutamine (10 +/- 3 micrograms/kg-min), and milrinone (67 +/- 13 micrograms/kg-min) sequentially to 10 patients with severe (NYHA class III or IV) congestive heart failure. Each agent led to a significant (p = .001) increase in cardiac index (1.9 +/- 0.5 to 2.7 +/- 0.6 liters/min/m2; 1.7 +/- 0.4 to 2.6 +/- 0.6 liters/min/m2; and 1.8 +/- 0.5 to 2.7 +/- 0.5 liters/min/m2, for nitroprusside, dobutamine, and milrinone, respectively). Dobutamine did not produce a significant change in the pulmonary capillary wedge pressure (27 +/- 5 to 24 +/- 6 mm Hg, NS) nor in mean arterial pressure (83 +/- 9 to 86 +/- 10 mm Hg, NS), but caused a significant rise in heart rate (85 +/- 16 to 99 +/- 17 beats/min, p = .001) and in myocardial oxygen consumption (8.7 +/- 2.1 to 11.1 +/- 3.8 ml O2/min, p = .03). In contrast, nitroprusside and milrinone each caused a significant (p = .001) fall in the pulmonary capillary wedge pressure (27 +/- 6 to 19 +/- 7 mm Hg and 26 +/- 6 to 19 +/- 9 mm Hg, respectively), without significantly increasing either the heart rate (87 +/- 18 to 85 +/- 17 beats/min and 86 +/- 17 to 89 +/- 17 beats/min, respectively) or myocardial oxygen consumption (8.8 +/- 2.3 to 7.6 +/- 2.1 ml O2/min and 8.8 +/- 2.1 to 8.4 +/- 2.1 ml O2/min, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)