CLINICAL-SIGNIFICANCE OF ELECTROCARDIOGRAPHIC T-WAVE NORMALIZATION WITH EXERCISE

A change from inverted T waves at rest to an upright position with exe rcise, has been debated to be a sign of myocardial ischemia. Retrospec tive analysis has been performed on exercise thallium-201 myocardial s cintigrams from 82 consecutive patients with T-wave inversion of at le ast 1 mm or more on their resting electrocardiogram (ECG) and normaliz ation with exercise. Ischemia was indicated by a transient myocardial perfusion defect with exercise, and probable scar was indicated by a f ixed myocardial defect. This gave four groups: (I) 30 patients had no defects; (II) 36 patients had fixed defects alone; (III) 2 patients ha d transient defects alone, and (IV) 15 patients had both fixed and tra nsient myocardial perfusion defects. Sixty-six out of 83 (80%) studies with normalization demonstrated no transient myocardial perfusion def ect. T-wave normalization occurred often in the leads corresponding to the area of fixed myocardial perfusion defect (77% in group II and 80 % in group IV). In 33 patients with coronary angiography, correlation was similar with T-wave normalization found in the distribution of cor onary artery disease in 77%. Compared to 251 consecutive patients unde rgoing exercise thallium testing for suspected coronary artery disease , the study group had a similar frequency of scans without defects, bu t relatively more studies with fixed relative to transient defects. We conclude that normalization is a nonspecific finding which may be ass ociated with coronary artery disease and fixed myocardial perfusion de fect. T-wave normalization with exercise has poor positive predictive value for the diagnosis of transient myocardial perfusion defect.