REGIONAL EJECTION FRACTION - QUANTITATIVE RADIONUCLIDE INDEX OF REGIONAL LEFT-VENTRICULAR PERFORMANCE

Radionuclide measurements of regional left ventricular ejection fraction were evaluated as a quantitative index of regional left ventricular function. Left ventricular ejection fractions were derived from background-corrected, time-activity curves in 43 patients assessed by both gated equilibrium radionuclide angiocardiography and left ventricular contrast angiography. From a single, modified left anterior oblique projection, the regional change in background corrected counts was determined in each of three anatomic regions. The normal range for regional radionuclide ejection fraction was determined in 10 patients with normal contrast ventriculograms and without obstructive coronary artery disease at coronary arteriography. Regional ejection fraction was compared with percent segmental axis shortening and extent of akinetic segments in corresponding regions of the contrast ventriculogram. Radionuclide and roentgenographic methods were in agreement as to the presence or absence of abnormal wall motion in 83 of 99 left ventricular regions (84%) in 33 patients evaluated prospectively. Comparison of regional ejection fraction demonstrated significant differences between regions with roentgenographically determined normokinesis (75 ± 3%, mean ± SEM), hypokinesis (44 ± 3%, p<0.0005) and akinesis (24 ± 5%, p<0.005). We conclude that the left ventricular regional ejection fraction provides a reliable quantitative assessment of regional left ventricular performance.