The hemodynamic responses to esmolol, an ultrashort-acting (t1/2 = 9 min) beta 1-adrenergic receptor antagonist, were examined in 16 patients with myocardial ischemia and compromised left ventricular function as evidenced by a mean pulmonary capillary wedge pressure of 15 to 25 mm Hg. Esmolol was infused intravenously to a maximal dose of 300 micrograms/kg body weight per min for less than or equal to 48 h in 16 patients: 9 with acute myocardial infarction, 6 with periinfarction angina and 1 with acute unstable angina. The sinus rate and systolic arterial pressure declined rapidly in all patients from baseline values of 99 +/- 12 beats/min and 126 +/- 19 mm Hg to 80 +/- 14 beats/min (p less than 0.05) and 107 +/- 20 mm Hg (p less than or equal to 0.05) during esmolol treatment. Rate-pressure product decreased by 33% and cardiac index by 14% during esmolol treatment, but pulmonary capillary wedge pressure was not significantly altered by drug infusion (19 +/- 3 mm Hg at baseline versus 19 +/- 5 during treatment, p = NS). In all patients there was a rapid return toward baseline hemodynamic measurements within 15 min of stopping administration of esmolol, and virtually complete resolution of drug effect was evident within approximately 30 min. During infusion of esmolol, four of nine patients receiving intravenous nitroglycerin required downward adjustment of nitroglycerin infusion rate to maintain systolic blood pressure greater than 90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)