Similarity of electrocardiographic changes in demand ischemia and supply ischemia caused by left main or 3-vessel disease

Abstract

patients with coronary artery disease, those with chest pain and ST-segment depression during atrial pacing had an increase in the left ventricular end-diastolic pressure (LVEDP), whereas those without ischemia showed no increase. This indicates that ST-segment depression was caused by an increase in LVEDP. Extensive supply ischemia, for example, caused by sudden obstruction of the left main coronary artery, impairs the relaxatio n of the left ventr icle. 3 The resultin g increase in LVEDP induces severe subendocardial ischemia. In animals, a constriction of the left main coronary artery, causing global left ventricular ischemia, resulted in a significant decrease in the endocardial-to-epicardial flow ratio and a significant incre ase of end-diasto lic left ventricul ar trans mura l press ure. 4 Nikus et al have shown that the ECG pattern of STsegment depression and inverted T waves, maximally in leads V4 to V5, was strongly associated with left main or severe 3-vess el disea se ( Fig. 2). 5 ST-segment elevation in