抄録
Since Wood and Wolferth pointed out that huge T-waves were one of features indicative of injury in acute or subacute myocardial infarction, this finding has occasionally been considered as an important diagnostic feature.Smith found that the T-deflection increased, immediately after ligation of the coronary artery, in proportion to the magnitude of the ligated artery, and that the T deflection exceeded the R deflection when a large coronary artery was ligated.One hundred cases with upright high T-waves exceeding 10 mm. in the left precordial leads were indiscriminately selected; a through clinical history and physical examination as well as Levy's anoxemia test and/or Master's two step exercise test were done to examine as to whether correlation between high T-waves and myocardial lesion exists or not. The incidence of high T-waves in each decade of age was checked; in the age group below 39, the incidence was 3.9%. There were 45 cases with a chief complaint of angina pectoris, being highest in frequency among others. There were many patients with rheumatic heart disease or angina pectoris vera as a basic cardiac lesion.In all subjects high T-waves were observed over 24 hours after the onset of symptoms. In three of these cases, high T-waves were still observed two or three years after the beginning of observation, precordial discomfort was a frequent complaint in these patients. The amplitude of the T-waves in the chest leads ranged from 1.5 to 13.4 mm. as observed in our material.In 52 of 100 cases the electrocardiogram at rest was normal.In 21, slight displacements of the ST junction which do not exceed the normal limits were recorded.In the other cases left ventricular hypertrophy, right ventricular hypertrophy or arrhythmia were present accompanying high T-waves.Levy's anoxemia test or Master's two step exercise test or both were carried out on 50 of 100 subjects. There were 16 cases with positive response to both of the tests; 22 cases with either one of the tests positive. To eliminate electrolyte unbalance particularly hyperkalemia as a cause of high T-waves, electrolyte levels were measured and none of the subjects revealed this abnormality. To produce experimental coronary insufficiency, incomplete ligations of the coronary artery of canine hearts were carried out. No significant changes developed immediately after ligation; marked increase in the height of T deflection occurred after 24 hours, though changes in the ST segment were slight.These findings appear to correspond to what Bayley pointed out that changes in the T-waves are predominant rather than ST in myocardial ischemia due to coronary insufficiency.Thus, it was consluded that huge upright T-waves may be a diagnostic index not only in the early stage of myocardial infarction, but also in a healing myocardial infarction of coronary insufficiency.
