The Effect of Propranolol on Ecg in Angina Pectoris and Orthostatic Tachycardia1

The effect of intravenous infusion of 5 mg propranolol on the electrocardiogram at rest, during and after work on a bicycle ergometer was studied in 26 patients with either typical or questionable coronary heart disease or with orthostatic tachycardia. In the last group electrocardiograms were also registered in the upright position. In the patients with orthostatism propranolol elicited a normalization of the S‐T and T changes in standing position and during work. Propranolol had no demonstrable effect on the electrocardiographic picture during work in patients with typical coronary disease though it did elicit a significant reduction of the depressed S‐T and T segments three minutes after work. This observation may be connected with the possibility that the cardiac work, and hence the degree of ischemia, was less in the work test after propranolol compared with that before. In the patients with questionable coronary disease propranolol elicited a reduction of the electro‐cardiographic changes both during and after work. Such an effect would be in line with the presence of an increased activity in the cardiac sympathetic nerves and possibly also with a moderate degree of coronary sclerosis.