Abstract
Left ventricular ejection fractions (LVEF) were measured after injection of a bolus of Tc-99m gluconate. These ejection fractions were then compared to values obtained by contrast angiography. The importance of such parameters as delivery of the bolus, collimation, projection used, and parameters chosen for subsequent data analysis were evaluated. We found that results were most critically dependent upon delivery of radioactive bolus and background selection. Correlation of LVEF obtained in the LAO-20° view to values obtained at the time of catheterization provides a statistically significant relationship.