Intravenous propranolol therapy for acute myocardial infarction in man: hemodynamic and serial creatine kinase assessment.

Propranolol was administered intravenously to 12 patients with presumed acute myocardial infarction in the attempt to limit infarct size. Patients' conditions were uncomplicated (heart rate greater than or equal to 60/min, systolic blood pressure greater than or equal to 100 mm Hg, mean pulmonary capillary wedge pressure mean [PCWP] less than or equal to 20 mm mercury). The aim was to produce beta-blockade that was early, complete, and continuous. Target loading dose was achieved in seven patients and full maintenance was achieved in six patients. The remaining patients received smaller loading or maintenance doses or both because of varying degrees of bradycardia, hypotension, or elevated mean PCWP. Myocardial CK release in the propranolol group was 2651 mIU/ml +/- 843 (mean +/- SE, n = 12) vs 2987 mIU/ml +/- 422 in 21 comparison patients, a difference not statistically significant. The time to CK plateau (completion of infarction) was related to total CK release in both propranolol and comparison patients.