冠状动脉痉挛致心肌血流灌注降低:反向再分布的机制研究

Objective To investigate the mechanism of reverse redistribution (RR) on dipyridamole 201Tl myocardial perfusion studies in the patients with coronary artery spasm. Methods Twenty-six patients with coronary artery spasm and presented as RR on dipyridamole 201Tl myocardial perfusion studies were enlisted as RR group, while other 16 patients with no coronary artery stenosis nor RR were enlisted as control group. Dipyridamole test was repeated during coronary angiography. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and TIMI myocardial perfusion grade (TMPG) were measured at RR related and non-RR related coronary arteries before and after dipyridamole infusion respectively.All of the data were analyzed by Student's t-test orχ2-test and correlation analysis. Results Coronary artery angiography showed slower blood flow and lower myocardial perfusion in RR related vessels when compared with non-RR related vessels in RR group, but there was no significant difference among the main coronary arteries in control group. The perfusion defects of RR area at rest were positively related to slowerblood velocity at corresponding coronary arteries ( r = 0.79, t = 10.18, P ＜ 0.001 ). In RR related vessels,CTFC were (36 ±6) frames and (26 ±7) frames (t =4.15, P ＜0.01 ), while TMPG were (2.02 ±0.39)grades and (2.92 ± 0.12) grades ( t = 2.25, P ＜ 0.05 ) before and after dipyridamole infusion, respectively.In non-RR related vessels, CTFC were (29 ±7) frames and (25 ±5) frames (t =2.31, P ＜0.05), while TMPG were (2.56 ± 0.31 ) grades and (2.96 ± 0.06) grades ( t = 2.17, P ＜ 0.05 ) before and after dipyridamole infusion, respectively. However, there were no significant changes of CTFC and TMPG before and after dipyridamole infusion in control group ( t = 0.932, 0.867, respectively, both P ＞ 0.05 ). Conclusion RR is related to the decreased blood flow and myocardial perfusion induced by coronary artery spasm at rest,which may be improved by stress test such as intravenous dipyridamole infusion.

Reverse 201Tl myocardial redistribution induced by coronary artery spasm