A series of transient electrocardiographic changes are reported which simulate those obtained during experimental temporary coronary artery occlusion in animals. The patient in whom they were recorded was experiencing episodes of syncope and atypical anginal pain and displayed no signs of myocardial infarction. Similar fleeting electrocardiographic abnormalities suggesting myocardial infarction have been reported in the literature as occurring in angina pectoris. A review of the published data indicates that a more serious disturbance of the coronary circulation is responsible, best described as the syndrome intermediate in degree between transient myocardial ischemia responsible for angina pectoris and coronary occlusion producing myocardial infarction.