Effects of sodium nitroprusside on left ventricular size and performance in myocardial infarction determined by ultrasound

Sodium nitroprusside, a peripheral arteriolar and venous vasodilator, has been extensively applied in the treatment of congestive heart failure accompanying acute myocardial infarction. Although nitroprusside has been documented to reduce left ventricular volume by cineangiography in patients with chronic congestive heart failure secondary to coronary artery disease, no data is available regarding left ventricular volume changes induced by nitroprusside in acute myocardial infarction patients. Therefore we evaluated the effects of nitroprusside upon intracavitary left ventricular size and cardiac performance by echocardiography in 10 acute myocardial infarction patients, and compared these results to data obtained by simultaneous right heart catheterization. Echocardiographic scans were obtained in a standard fashion with a commercially available echograph with patients in the 10° total body tilt position, and catheterization was performed utilizing a Swan-Ganz catheter. Nitroprusside infusion (30–200 micrograms/minute) produced a fall for the group of patients in mean pulmonary wedge pressure (20–13 mm Hg p<.01) and a reduction in mean systemic blood pressure (90 to 80 mm Hg, p<.01), but did not alter heart rate (98.9) or either cardiac output (4.1) or stroke index (26.1) obtained by dye dilution techniques.