ASSESSMENT OF VIABLE MYOCARDIUM AND PREDICTION OF POSTOPERATIVE IMPROVEMENT IN LEFT-VENTRICULAR FUNCTION IN PATIENTS WITH SEVERE LEFT-VENTRICULAR DYSFUNCTION BY QUANTITATIVE PLANAR STRESS-REDISTRIBUTION-REINJECTION 201-TL IMAGING

A noninvasive approach to determine viable but asynergic myocardium wi ll be clinically significant in identifying patients with coronary art ery disease and severe left ventricular dysfunction who will benefit m ost from coronary bypass surgery. Accordingly, 12 patients (mean eject ion fraction 0.32+/-0.03) underwent quantitative planar stress-redistr ibution-reinjection thallium scintigraphy and radionuclide ventriculog raphy before and 8 weeks after revascularization for viability and seg mental and global left ventricular function assessment, respectively. Reinjection scan showed new fill-in in 63% of segments without redistr ibution. Postoperative improvement in perfusion and function of asyner gic segments were significantly better in viable compared to nonviable segments (P<0.001, P<0.01, respectively) with a strong correlation be tween improvement in 201-Tl uptake and function (P<0.001). When adequa cy of revascularization was considered, the predictive value of a posi tive preoperative viability test for functional improvement was 83%. F inally, mean ejection fraction and global wall motion score increased significantly after revascularization for the group as a whole (0.32+/ -0.03 to 0.44+/-0.04, P<0.001 and 24.08+/-2.90 to 33.16+/-3.32, P<0.00 1, respectively). Thus, preoperative quantitative planar stress-redist ribution-reinjection thallium imaging detects viable but asynergic seg ments which improve function postoperatively and may be valuable in se lection of patients with severe left ventricular dysfunction for revas cularization. Copyright (C) 1997 Elsevier Science Ireland Ltd.