Evaluation of left ventricular function (ejection fraction and segmental wall motion) by single pass radioisotope...

Changes in ejection fraction (EF) and segmental wall motion (SWM) have been shown to be sensitive indicators of left ventricular (LV) function. This information is only obtainable by contrast angiography or gated blood pool scans. Gated studies assume a fixed geometry for the LV for EF determinations, are lengthy and limited primarily to the LAO projection. We correlated contrast and Tc-99m pertechnetate angiograms by singl pass radioisotope angiography (immediately preceding the contrast study) in 12 patients. EF was calculated from the LV time/activity curve and values ranged from .21 to .72. Angiographic correlation yielded r = 0.97. Regional LV wall motion was evaluated by dividing a summated cardiac cycle into 16 frames and dynamically and sequentially displaying these frames. Regional wall motion evaluation of four LV quadrants correlated well with angiography (r = 0.97). For quantitation these images were divided into four anterior and four inferior segments and the areas of respective segments were compared and expressed as a shortening fraction. SWM compared favorably with angiographic determinations (r ranged from 0.70 to 0.99). Thus, single pass radioisotopic determinations of EF and SWM in the RAO projection correlated well with the angiographic values and provide essential quantitative information of LV function otherwise unobtainable at the bedside.