Effect of atenolol on recovery of the electrocardiographic signs of myocardial infarction.

The most notable changes in the 35-lead precordial electrocardiogram in 22 subjects in the first 6--12 months after acute myocardial infarction were a reduction in the amplitude of Q waves and a significant increase in the amplitude of the R waves. Patients who, in a random trial, had been given 100 mg atenolol daily from admission showed a significantly greater recovery in R-wave amplitude and decrease in Q waves than patients given placebo. It is concluded that atenolol improves the recovery of the electrocardiographic signs of myocardial infarction.