Abstract
he effect of aorto-coronary bypass graft surgery was studied in 15 patients using exercise Tl-201 myocardial imaging (Ex Tl-TM). Patients were exercised in the upright position on a bicycle ergometer until the onset of limiting symptoms. Myocardial imaging was performed using SEARLE-LFOV scintillation camera and a high-sensitivity parallel-hole collimator.
Before the operation, ischemic lesion was detected by Ex Tl-IM in 13 of 15 patients (87%) on initial image, and the redistribution was observed in 9 of 13 patients (69%) on delayed image. But it was difficult to detect ischemic area in non-infarcted lesion in 1 of 5 patients (20%) with previous myocardial infarction.
After the operation, Ex Tl-IM could predict grafts patency in 5 of 6 (83%) with improved myocardial perfusion, and graft occlusion in 2 of 3 patients (67%) without improved perfusion.
We conclude that Ex Tl-IM is a useful technique to evaluate improvement of myocardial perfusion after aorto-coronary bypass graft surgery.
