Preoperative propranolol therapy and aortocoronary bypass operation.

The relationship between long-term propranolol hydrochloride therapy and subsequent coronary bypass operation was prospectively investigated in 119 patients who were grouped three ways: propranolol therapy continued in full dosage to operation (group A), propranolol therapy discontinued or tapered 24 to 72 hours preoperatively (group B), and no preoperative propranolol therapy (control group). During preoperative hospitalization, one patient in each group A and the control group suffered an increase in anginal symptoms compared with 15 patients in group B, three of whom also had new ventricular arrhythmias. During anesthesia up to the period of cardiopulmonary bypass, 26% of group A patients showed signs of ischemia (eg, ST segment deviation or ventricular arrhythmias) as compared with 51% of the control group and 70% of group B. Hypotension and bradycardia were not more common in group A patients. No differences among groups were noted in case of emergence from bypass, need for cardiac stimulants, or mortality.