ST Segment Change on Treadmill Exercise Electrocardiogram and Coronary Arteriographic Findings in Patients with Angina Pectoris

Kim, Young Kwon; Joo, Seung Jae; Cho, Myeong Chan; Kim, Chee Jung; Kim, Cheol Ho; Choi, Yun Shik; Lee, Young Woo

Abstract

Although exercise electrocardiography is commonly used to determine the likelihood of coronary artery disease, data of exercise electrocardiography are limited in Korea. Authors reviewed 409 patients with chest pain who underwent 12 lead treadmill exercise electrocardiography and coronary arteriography at Seoul National University Hospital from January, 1984 through September, 1990. All the patients underwent catheterization within three months after having a standard Bruce protocol treadmill exercise test. None of them had prior myocardial infarction, valvular heart disease, cardiomyopathy, and complete left bundle branch block. The study subjects consisted of 208 patients, including 42 patients of coronary artery spasm, with no or insignificant fixed coronary artery stenosis(less than 50% narrowing of luminal diameter), and 201 with significant fixed stenosis. The results were as follows; 1) The sensitivity of treadmill exercise electrocardiography was 73.6%, and the specificity was 88.2%. Positive exercise test in coronary artery spasm was 21.4%. 2) With increasing the extent of coronary artery disease, the proportion of the patients with one-vessel disease who showed positive ST segment change of stage I increase. Most of the patients with one-vessel disease who showed positive ST segment change on stage I had 90% or more stenosis. 3) With increasing the extent of coronary artery disease, the proportion of the patients with positive ST segment change in multiple lead groups increased. 4) ST segment change appeared most frequently in lead group V4-V6 and next in lead group II III a VF regardless of involved arteries. 5) ST segment elevation in lead group V1-V3 or in I/aVL was usually associated with 90% or more stenosis of left anterior descending artery in one-vessel disease, but similar proportion of the patients was noted in multivessel disease. This suggests that ST segment elevation in lead group V1-V3 or in I/aVL is probably associated with severe ischemia, not a specific predictor of left anterior descending coronary artery disease.