Significance of T wave normalization in the electrocardiogram during exercise stress test.
Although normalization of previously inverted T waves in the ECG is not uncommon during exercise treadmill testing, the clinical significance of this finding is still unclear. This was investigated in 45 patients during thallium-201 exercise testing. Patients with secondary T wave abnormalities on the resting ECG and ischemic exercise ST segment depression were excluded. On the thallium-201 scans, the left ventricle was divided into anterior-septal and inferior-posterior segments; these were considered equivalent to T wave changes in leads V1 and V5, and aVF, respectively. A positive thallium-201 scan was found in 43 of 45 (95%) patients and in 49 of 52 (94%) cardiac segments that showed T wave normalization. When thallium scans and T wave changes were matched to sites of involvement, 76% of T wave normalization in lead aV, was associated with positive thallium scans in the inferior-posterior segments, and 77% of T wave normalization in V1 and V5 was associated with positive thallium scans in the anterior-septal segments. These site correlations were similar for reversible and fixed thallium defects, and for patients not on digoxin therapy. Similar correlations were noted for the sites of T wave changes and coronary artery lesions in 12 patients who had angiography. In patients with a high prevalence for coronary artery disease, exercise T wave normalization is highly specific for the presence of the disease. In addition, it represents predominantly either previous injury or exercise-induced ischemic changes over the site of ECG involvement, rather than reciprocal changes of the opposite ventricular wall.
Marin
J J
JJ
Department of Medicine, Veterans Administration Medical Center, Sepulveda, CA 91343.
Heng
M K
MK
Sevrin
R
R
Udhoji
V N
VN
D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003327:Coronary Disease / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes