The effect of alprenolol on serum myoglobin levels in acute myocardial infarction

In a group of 37 patients with definite acute myocardial infarction (AMI) allocated to treatment with either alprenolol (n = 20) or placebo (n = 17) serial determinations of concentrations in serum of myoglobin (S-Mb), creatine kinase (S-CK), aspartate aminotransferase (S-ASAT) and lactate dehydrogenase (S-LDH) were performed. The median peak levels of S-Mb, S-CK and S-LDH were significantly (P less than 0.05) lower among patients treated with alprenolol. The median of the estimated infarct size based on S-CK curves was also significantly (P less than 0.01) lower in the alprenolol group. There was no significant difference between the estimated infarct size based on S-Mb values in the two groups. It is concluded that the present study provides indirect evidence for the assumption that early beta-blockade in AMI can reduce infarct size.