Radionuclide evaluation of left ventricular synergic pumping efficiency during acute myocardial infarction.

The clinical value of an index of left ventricular synergic pumping efficiency (EFF) was evaluated in 50 patients with uncomplicated myocardial infarction in which radionuclide ventriculography was performed within 72 h of the onset of the infarction and between 7 and 13 days post infarction. EFF was defined as the ratio of global left ventricular stroke volume to the magnitude of all intraventricular blood pool variations measured on a pixel by pixel basis. EFF correlated better with a subjectively evaluated wall motion index (r = 0.84) than did the ejection fraction (EF) measurements (r = 0.69). In all patients, but most significantly in patients with inferoposterior infarctions, EFF measurements in the acute phase were a better predictor of the predischarge ventricular performance than the EF measurements. The left ventricular EFF is a reliable parameter to quantitate the effect of regional wall motion disturbances on global ventricular function in a standardized manner.