Effect of Propranolol on "Nonspecific" S-T Segment and T-Wave Changes: Differentiation of Coronary from Noncoronary ECG Changes

¹ Institute of Cardiology, Chaim Sheba Medical Center, Tel-Hashomer; Tel-Aviv University Medical School, Israel

This study evaluated the effect of propranolol 10 to 20 mg per os, on so-called nonspecific S-t segment and T-wave changes in patients suspected of having coronary insufficiency. One hundred forty three subjects were tested. Of these, 41 patients with definite heart disease (31 coronary patients and ten with left heart hypertrophy and strain) served as a control. One hundred two patients with nonspecific S-T-T changes to be evaluated were divided into two subgroups according to their clinical history: 53 of these patients had no clinical history of heart disease and had precordial pain clinically not suggestive of coronary insufficiency; 49 patients, in whom, on clinical grounds, the diagnosis of coronary insufficiency remained doubtful and agnina pectoris could not be definitely excluded. No patients in the control group reverted to normal ECG patterns after propanolol. In most subjects in whom, on clinical grounds, angina pectoris could be excluded, the ECG pattern reverted to normal. In the doubtful cases, both clinically and electrocardiographically, a good separation of coronary from nancoronary could be established. The mode of action and the rationale of this test, as well as its clinical significance, are discussed.