[Thrombolysis and beta-block in acute myocardial infarct. Their effects on left ventricular function].

The effects of metoprolol or streptokinase or the combination of both drugs on left ventricular function and the rescue of the jeopardized myocardium in patients with acute myocardial infarction (AMI) were compared. Thirty-seven patients with AMI were allocated in 3 different groups: 19 received 15 mg of metoprolol i.v. in 15 minutes, 7 were treated with 1.5 million IU i.v. of streptokinase and 11 more received both drugs. The following variables were studied at control and one and twenty-four hours after treatment; blood pressure, heart rate, "double product", systolic time intervals, diastolic time and the sum of ST-segment elevation and the sum of the R wave in the EKG. Blood pressure, heart rate and "double product" decreased in the groups treated with metoprolol. The pre-ejection time/ejection time index did not change in any group. The diastolic time increased with metoprolol and the sum of ST-segment elevation was more reduced with the combined treatment. Also in this group, the sum of R wave did not decrease as it happened in the other 2 groups. It is concluded that the combination of streptokinase and metoprolol was more effective in the rescue of jeopardized myocardium than metoprolol or streptokinase administered alone.