Electrocardiograms with large, upright T waves and long Q-T intervals

Abstract It is suggested, on the basis of the experimental results of cooling or warming the endocardial surface of the dog's left ventricle, that large, upright T waves in the human electrocardiogram, together with prolongation of the Q-T interval, may oftent be due to ischemic changes preponderantly involving the muscle layers at the endocardial surface of the left ventricle. The best examples of electrocardiograms of this type were obtained from patients with arterial hypertension and symptoms and signs of encephalopathy. Further study is needed before the reason for this association can be suggested.