Measurement of Myocardial Blood Flow in Animals and Man by Selective Injection of Radioactive Inert Gas into the Coronary Arteries.

• The Kety-Schmidt method for measurement of regional blood flow was first applied to the heart by Eckenhoff et al. These investigators employed coronary sinus catheterization to measure myocardial blood flow with nitrous oxide. The use of a radioactive gas and an external detector for the measurement of organ blood flow was investigated by Conn, Lewis et al., and Lassen et al. The radioactive gas, krypton, along with precordial counting was employed to measure myocardial blood flow in dogs by Herd et al.° These investigators injected solutions of radioactive gas into the coronary arteries through chronically implanted plastic catheters. The current report will confirm the results of Herd and describe animal experiments designed to further validate the method and report measurements of myocardial blood flow made in 18 patients during the course of selective coronary arteriography. Solutions of xenon'' or krypton were injected directly into the coronary arteries through the arteriographic catheter, and the disappearance of the gas from