REVERSE REDISTRIBUTION IN RESTING TL-201 MYOCARDIAL SCINTIGRAPHY IN CHRONIC CORONARY-ARTERY DISEASE - AN INDEX OF MYOCARDIAL VIABILITY

The aim of this study was to evaluate whether segments with reverse re distribution on rest-redistribution (TI)-T-201 scintigraphy represent viable tissue or scar. Methods: Nineteen patients (17 men, 2 women; me an age 53 +/- 8 yr) with coronary artery disease underwent rest-redist ribution (TI)-T-201 study before coronary revascularization. Regional (TI)-T-201 uptake was analyzed quantitatively. Regional left ventricul ar wall motion was assessed before and after coronary revascularizatio n using two-dimensional echocardiography and a three-point scale (1 = normal, 2 = hypokinetic, 3 = akinetic/dyskinetic). Two patterns of rev erse redistribution were identified: pattern with normal (TI)-T-201 up take in rest and abnormal in redistribution images and pattern with ab normal (TI)-T-201 uptake in rest and a significant decrease in redistr ibution images. Results: Of the 247 segments analyzed, 85 were classif ied as normal, 37 as reversible defects, 83 as fixed defects and 42 as reverse redistribution (19 RR-A, 23 RR-B). Segments with RR-A differe d from those with RR-B in wall motion score (1.4 +/- 0.7 versus 2.0 +/ - 1.0). Electrocardiographic Q-waves were present in 26% of segments w ith RR-A and in 57% of segments with pattern B. After revascularizatio n, all dyssynergic segments with pattern A showed improved wall motion , while only 40% of segments with pattern B and abnormal wall motion h ad such improvement. Conclusion: Our results suggest that dyssynergic segments with pattern A should be considered viable, while more cautio n should be used in classifying those with pattern B.