Abstract: To observe myocardial viability in infarcted area in patients with older myocardial infarction,we perfomed pilot study to identify the severely ischemic myocardium using the infusion of a thallium glucose insulin potassium solution.Results were compared with those obtained in rest images. In 336 segments of 28 patients ²⁰¹Tl rest images,45 out of 119 infarction segments,revealed ²⁰¹Tl activity after GIK infusion 37.8%。 In 180 segments of 15 patients with PTCA or CABG,28 out of the 76 infarction segments revealed ²⁰¹Tl activity after GIKinfusion 36.8%。42% segments with rest images were detected after operation.These results confirm that continuous infusion of ²⁰¹Tl with a low dose of insulin in a glucose and potassium chloride solution is safe and may enhance cellular uptake of the radiotracer in severely ischemic regions especially in older myocardial infarction.This study suggests that within the old infarcted area,there still exists viable myocardium.

Key words: older myocardial infarction, viable myocardium, ²⁰¹ Thallium GIK, myocardial scintigraphy