Probe radiocardiography: validation of a technique to routinely determine left ventricular ejection fraction.

We investigated the probability of obtaining a valid radiocardiogram with the first commercially available cardiac probe and a peripheral injection of the radiopharmaceutical. Measurements of left ventricular ejection fraction (LVEF) were obtained in a series of 15 patients undergoing cardiac catheterization. Probe LVEF determinations using central, peripheral and rapid sequential injections correlated well with each other and with ventriculography (r = .88--.98). By documenting its accuracy and precision, this study confirms the validity of a new technique for measuring LVEF.