Right ventricular ejection and regional wall motion evaluated by cardiac blood pool emission computed tomography

Using technetium-99m ECG-(dual)gated cardiac blood pool emission computed tomography (ECT), right ventricular (RV) ejection fraction (EF) and % shortening of the RV were calculated for the evaluation of RV function in 10 patients with ischemic heart disease, three patients with dilated cardiomyopathy (DCM), and eight normal subjects. Left ventricular ejection fraction, calculated in the same method as RVEF, was well correlated with contrast cineangiography (r = 0.69) and conventional multigated method (r = 0.90). Decreased RVEF, calculated by cardiac blood pool ECT, was occasionally associated with RV function disturbance, as shown by positive uptake on Tc-99m PYP sicntigraphy, occlusion of the right coronary artery, and RV dilation on echocardiography. A decrease in % shortening of the interventional septum and RV free wall was observed in association with decreased RVEF. Such a decrease in RV wall motion in both the septum and free wall suggests their involvement in the decrease of RVEF. The results indicate the validity of cardiac blood pool ECT in the evaluation of RV function. (Namekawa, K.)