Left main coronary artery disease: radionuclide angiographic function versus anatomic correlates with visual and quantitative angiographic methods.

The results of exercise radionuclide angiography in 29 patients with significant left main coronary artery stenosis were examined to correlate functional left ventricular performance with anatomic severity of left main coronary artery stenosis. Change in ejection fraction, regional wall motion, and peak ejection fraction were widely variable; none of these parameters correlated with severity of left main stenosis as assessed by visual or quantitative angiographic methods. Twenty-five patients (86%) had two or more of the following indicators of ischemia with exercise: chest pain, significant ST-segment depression, systolic hypotension, definite decrease in ejection fraction, or definite decline in regional wall motion. However, four patients (14%) had only mild abnormalities in ejection fraction and regional wall motion, although they did have hemodynamic and electrocardiographic evidence of severe ischemia. Exercise radionuclide angiography yields heterogeneous results in patients with significant left main coronary artery stenosis. Anatomically severe left main coronary artery stenosis is not always associated with mechanical evidence of severe ischemia.