A Comparative Study of Cardioselective β‐Blockade and Diazepam in Patients with Acute Myocardial Infarction and Tachycardia

Abstract

Patients (87) with an acute myocardial infarction and a pulse rate of .gtoreq. 80/min on admission were randomly allotted to one group given a cardioselective .beta.-blocker [practolol], a 2nd group given diazepam and a 3rd group given placebo. The 3 groups were comparable in age, sex distribution, previous history of ischemic heart disease, initial pulse rate, blood pressure, pain index, enzyme values and degree of ST elevation. The acute mortality (within 10 days) did not differ between the groups. The drug treatment elicited no reduction of infarct size, as judged from enzyme levels, degree of reduction of ST elevation, or physical exercise capacity. The reasons for this negative result are discussed. In routine clinical practice the therapeutic intervention may start too late after onset of symptoms. A beneficial effect on mortality among patients whose treatment started early after onset of symptoms supports this conclusion.