Kubota Y, Sugihara H, Azuma A, Katahira T, Nakagawa T, Kawata K, Nakamura T, Furukawa K, Katsume H, Nakagawa M
Second Department of Medicine, Kyoto Prefectural University of Medicine.
J Cardiol. 1990;20(3):541-8.
For simple, non-invasive evaluations of coronary flow reserve during exercise, we investigated the coronary flow reserve index using the ratio of change of fractional distribution in the regional myocardium to oxygen demand. The subjects included 24 patients with effort angina pectoris and 11 normal volunteers. PTCA was performed for 11 patients. Using the biological properties of Tl-201, single photon emission computed tomography (SPECT) was performed at submaximal exercise and at rest by two successive injections of Tl-201 within a short time interval (double dose method). The correlation between the fractional distribution in the myocardium (delta-Fract) and the oxygen demand during exercise and at rest were evaluated. delta-Fract correlated well with the rate of change of the pressure rate product (delta-PRP), and delta-Fract/delta-PRP (CRI) was a good indicator of the coronary flow reserve index. CRI in the ischemic region correlated well with the percent area stenosis of the supplying coronary artery and improved with resolution of percent area stenosis of the target coronary artery after PTCA, but in some cases they were not above the normal range. CRI as obtained by exercise SPECT using the double dose method is useful for non-invasively estimating the coronary flow reserve during exercise, and it can be used for evaluating the effect before and after PTCA.
