Spatial distribution of exercise-induced ST-segment depression and U-wave inversion in identifying the ischemic site in patients with coronary artery disease.
Eighty-seven unipolar electrocardiograms were simultaneously recorded before and after symptom-limited treadmill exercise in 75 patients with coronary artery narrowing (greater than equal to 70%) and without previous myocardial infarction. Body surface distributions of ST segment depression were divided into 3 types; upper, lower, and diffuse types. Body surface distributions of U-wave inversion were divided into 2 types; upper, and lower types. These distribution patterns were compared with the location of ischemia determined by T1-201 exercise myocardial perfusion imaging. For ST-segment depression, a considerable number of patients had diffuse-type ST depression, whether the site of ischemia was anterior (22/32, 69%), inferior (18/27, 67%) or both (5/5, 100%). However, upper-type ST depression was associated with anterior ischemia, and lower-type ST depression, with inferior ischemia. The sensitivity and specificity of the spatial distribution of ST depression in identifying the myocardial ischemic site were 27% and 95% for anterior ischemia. The sensitivity and specificity of the spatial distribution of St depression in identifying the myocardial ischemic site were 27% and 95% for anterior ischemia respectively, and 28% and 88% for inferior ischemia, respectively. The incidence of U-wave inversion was moderate (29/75, 39%), but the distribution pattern was specific for the site of ischemia; upper-type U inversion associated with anterior ischemia, and lower type with inferior ischemia. The sensitivity and specificity were 59% and 100% for anterior ischemia respectively, and 22% and 100% for inferior ischemia respectively. By a combination of ST-depression and U-inversion, the sensitivity and specificity were 78% and 95% for anterior ischemia, and 44% and 88% for inferior ischemia. Body surface electrocardiographic mapping provided important information in the non-invasive diagnosis of the site of myocardial ischemia.
Ikeda
K
K
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Yamaki
M
M
Matsui
M
M
Hanashima
K
K
Nakamura
K
K
Tonooka
I
I
Meguro
M
M
Tsuiki
K
K
Yasui
S
S
D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000175:diagnosis*; D004562:Electrocardiography; D005080:Exercise Test; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D013794:Thallium Radioisotopes