Relationship between the ischemic threshold at the onset of wall-motion abnormality on semisupine exercise echocardiography and the extent of coronary artery disease

Abstract

Semisupine exercise echocardiography (SSEE) provides the unique opportunity of continuous monitoring of segmental wall motion during physiologic stress. We evaluated the relationship between the ischemic threshold at the onset of wall-motion abnormality on SSEE and the extent of coronary artery disease (CAD) in a consecutive series of 224 patients who underwent coronary angiography. Ischemic threshold was significantly lower for patients with multivessel disease compared with single-vessel disease: maximal workload was 102 versus 135 W (P = 1.3.10(-6)); percentage of maximal predicted heart rate achieved was 64 versus 70% (P =.004); and double product was 21,335 versus 23,389 (P =.03), respectively. Sensitivity, specificity, and positive and negative predictive values of SSEE for the detection of significant CAD (> or =60% diameter stenosis) were 81%, 74%, 90%, and 56%, respectively. SSEE is an accurate tool to diagnose CAD and the ischemic threshold at the onset of wall-motion abnormality is inversely related to the extent of CAD.