Noninvasive Regional Myocardial Perfusion with Radioactive Potassium

Abstract

Myocardial perfusion imaging after intravenously administered radioactive potassium (43K) was used to delineate noninvasively areas of myocardial infarction and left ventricular regions that become transiently ischemic during angina pectoris. Forty-three subjects were studied at rest and during maximal treadmill exercise. In 12 normal subjects 43K distribution was homogeneous both at rest and during exercise. In 13 of 15 patients with previous myocardial infarction studied at rest, regions of decreased radionuclide accumulation corresponded to the anatomic location of the infarct. In 16 of 19 patients with angina pectoris, regions of relatively decreased 43K accumulation were identified when the tracer was administered during exercise, but were not present at rest. These zones of relative hypo-perfusion corresponded to regions supplied by angiographically demonstrable stenotic coronary arteries in all patients so studied. 43K myocardial imaging thus provides a safe and simple noninvasive means of assessing regional myocardial perfusion at rest, with exercise and during angina pectoris. (N Engl J Med 288:809–812, 1973)