Indication of aorto-coronary bypass graft surgery for infarction area of myocardium considered from exercise thallium-201 myocardial imagings.

To assess accurately the indication and effects of aorto-coronary bypass graft surgery (ACBG) to the myocardium infarction area, 35 patients with myocardial infarction were analyzed by using exercise thallium-201 myocardial imagings. The patients were classified into group I (18 cases) and group II (17 cases) before ACBG. Group I consisted of patients with regional hypoperfusion in the initial image who showed redistribution in the delayed image to the infarction area of myocardium. Group II consisted of those with regional hypoperfusion in the initial image without redistribution in the delayed image. Group I showed a significant improvement in myocardial perfusion (p less than 0.01), pressure rate product (p less than 0.01), global left ventricular ejection fraction (p less than 0.01), segmental wall motion abnormality (p less than 0.01), and exercise tolerance when compared with those of group II before and after ACBG. The above study showed that the pre- operative redistribution of the infarction area in the delayed image suggests myocardial viability and ACBG will be effective.