Visual Assessment of Regional Myocardial Perfusion Utilizing Radioactive Xenon and Scintillation Photography

Abstract

A method was devised to visualize the areas of left ventricle supplied by various coronary arterial branches utilizing scintillation photography and an inert radioactive gas which distributes instantaneously between coronary blood and perfused myocardial cells. From 1 to 5 millicuries of ¹³³ Xe dissolved in saline solution was injected through a catheter into the anterior descending or posterior circumflex branch of the left coronary artery of 15 dogs. Scintillation images produced during arrival and washout of ¹³³ Xe in the various regions of the heart were recorded by an image intensifier scintillation camera and high speed television monitor and were reproduced on Polaroid film during replay of the videotape on an oscilloscope. The resulting scintiphotographs defined the region of the left ventricle supplied by the coronary arterial branch. In nine of the dogs acute myocardial infarctions were produced by occluding one or the other branch of the left coronary artery. When ¹³³ Xe was injected again into the coronary artery proximal to the occlusion, that area of the left ventricle that was deprived of nutrient blood flow was no longer visualized on the gamma-ray scintiphotograph. The results indicate that regional myocardial perfusion may be dynamically visualized in the intact animal.