Esmolol and intraoperative myocardial ischemia: a double-blind study.

Forty patients scheduled to undergo elective myocardial revascularization were included in a randomized, double-blind, placebo-controlled study to evaluate any influence of esmolol on the incidence of myocardial ischemia. Calibrated recordings of ECG leads II and V5 were continuously monitored with the QMED Monitor One TC (Qmed Inc, Clark, NJ) from the time of arrival in the operating room holding area through the induction of anesthesia, using a high-dose opioid technique, and until the initiation of cardiopulmonary bypass. One group received a bolus of esmolol, 1.0 mg/kg, followed by a continuous infusion of 100 micrograms/kg/min. The other group received a bolus and infusion of saline placebo of equal volume. The incidence of myocardial ischemia was not significantly different between the groups on arrival in the holding area, or at any study point. Heart rate, mean arterial pressure, and the number of patients developing myocardial ischemia during the course of the study also did not differ significantly between the groups. There were significant decreases in heart rate and mean arterial pressure compared with the awake baseline values in both groups during multiple study points. It is concluded that esmolol was ineffective at treating preexisting or new-onset myocardial ischemia at this dosage in this clinical setting.