Effect of acebutolol on dynamic ischemic ECG changes: a study using ambulatory twenty-four-hour ECG monitoring.

The clinical effect of the beta-adrenergic blocking drug acebutolol hydrochloride (SECTRAL) was studied in 18 patients with angina pectoris. Ambulatory 24-h ECG monitoring proved to be a useful method for assessing the efficacy of this drug in individual patients in their own daily stresses and environment. Patients were studied in the control state, after two weeks' treatment with placebo, and after two weeks' constant oral dose of the drug. It was found that acebutolol produced a significant decrease in ischemic ST segment depression in patients in whom good beta-blockade was achieved. The drug was less effective in patients in whom the heart rate response to exercise was not suppressed and in those with critical coronary artery obstructions.