CLINICAL-SIGNIFICANCE OF REVERSE REDISTRIBUTION PHENOMENON AFTER CORONARY-ARTERY BYPASS-GRAFTING

The reverse redistribution (RR) phenomenon is a decrease in thallium 2 01 uptake during redistribution compared with Tl-201 uptake immediatel y after exercise. We evaluated RR in 23 patients after coronary artery bypass grafting. Postoperative RR was present in 48% and was signific antly more common in patients with a history of myocardial infarction (62%). The patients were classified according to the presence (+) or a bsence (-) of RR. An analysis of left ventricular wall motion showed s ignificant improvement after coronary artery bypass grafting in the RR + group (n = 12) but not in the RR- group (n = 11). Quantitative myoca rdial viability was evaluated using the defect volume ratio, mean defe ct severity, and defect severity index. The preoperative defect volume ratio was higher in the RR+ group than in the RR-group (p < 0.05). in the RR- group, no improvement in these indices was observed after ope ration. In contrast, the RR+ group showed significant improvement in a ll three indices (p < 0.05). These results indicate that after coronar y artery bypass grafting, an adequate blood supply to the remaining my ocardium may induce RR. This phenomenon, therefore, may be a significa nt indicator of postoperative myocardial viability.