[Left anterior descending artery lesions estimated by the rest T map in patients with angina pectoris].

Abstract

T potential distributions (T map) based on 87-lead unipolar electrocardiograms over the body surface were analyzed in 25 cases of angina pectoris without a history of acute myocardial infarction. Ten cases (40%) were selected according to the characteristic T map finding, in which there is an island or bay formation of negative potential downward from the left shoulder into the positive area located on the chest anteriorly. Their coronary angiography (CAG) and left ventriculography (LVG) were reviewed. In three cases which received percutaneous transluminar coronary angioplasty (PTCA), paired T maps were obtained before and after this procedure. All 10 cases had significant stenosis (more than 90%) at proximal or mid-portion in the left anterior descending artery, and six cases had single vessel disease. Asynergy at anterolateral, apical or septal segment was shown in LVG in six cases (60%). Improvement of the lesion by a successful PTCA restored the normal T potential distribution. We conclude that the rest T map abnormality described above is closely related to ischemia at the anterior wall of the left ventricle and interventricular septum secondary to the lesions in the proximal or mid-portion of the left anterior descending artery. Therefore, the rest T map can be applied to estimate the extent of the coronary lesions and to further evaluate electrocardiographically the effect of PTCA on ischemia in the left ventricle.