The occurrence in angina pectoris of electrocardiographic changes similar in magnitude and in kind to those produced by myocardial infarction

Abstract

The pronounced electrocardiographic changes which sometimes occur during a paroxysm of angina pectoris indicate that the disturbance of the coronary circulation which occurs in this condition is at times as great as that produced by the sudden occlusion of a large coronary artery.Attacks of anginal pain may occur which are accompanied by pro-found alterations of the electrocardiogram under circumstances which make it necessary to assume that the attendant myocardial ischemia is due to a change in the caliber of the coronary arteries affected, rather than to an increase in the work of the heart alone.Nicotine or some other constituent of cigarette smoke sometimes induces coronary "spasm" in patients who are subject to angina pectoris.