冠心病患者^(201)铊心肌灌注显像反向再分布的机制探讨与临床意义

Mechanism and clinical significance of reverse redistribution of ^(201)Thallium myocardial perfusion imaging in patients with coronary heart disease

目的探讨冠心病^(201)铊(TI)心肌灌注显像反向再分布(RR)的机制及临床意义。方法 48例冠心病患者行^(201)TI心肌灌注显像负荷试验后,分为RR组23例和对照组25例。分别在^(201)TI心肌灌注显像负荷试验前、试验后即刻及试验后3 h测外周血内皮素-1(ET-1)/一氧化氮(NO)比值。所有患者负荷试验后1周内进行冠状动脉造影,比较两组校正心肌梗死溶栓疗法血流帧计数(CTFC)和心肌血流灌注积分(TMPG)。结果两组不同时间点的ET-1/NO比较,差异有统计学意义(P<0.05),两组均试验后即刻有所下降,试验后3 h升高;两组间ET-1/NO比较,差异无统计学意义(P>0.05)。冠状动脉造影显示RR组的CTFC和TMPG高于对照组(P<0.05)。结论血管内皮功能异常引起的血流速度以及心肌血流灌注的变化可能是影响冠心病患者^(201)TI心肌显像RR的原因。心肌显像RR现象对提示梗死血管开通、节段存在存活心肌具有一定的诊断价值。

Objective To investigate the mechanism and clinical significance of reverse redistribution （RR） of 201 Thallium （TI） myocardial perfusion imaging in patients with coronary heart disease （CHD）. Methods Forty-eight patients with CHD were divided into RR group（ n = 23 ） and control group （n = 25 ） after load test of ^201TI myocardial peffusion imaging. The ratios of peripheral blood endothelin-1 （ET-1） to nitric oxide（NO） were measured before load test of ^201TI myocardial perfusion imaging,instantly after test and at 3 hours after test, respectively. Coronary angiography was conducted in all cases within one week after load test. And the corrected thrombolysis in myocardial infarction（TIMI） frame count（CTFC） and TIMI myocardial perfusion grade（TMPG） were compared between two groups. Results In both groups,there was significant difference in the ratio of ET-1/NO among different time points（P 〈 0.05）. And the ratios of both groups decreased instantly after test,but increased at 3 hours after test. There was no significant difference in the ratio of ET-1/NO between two groups（P 〉0.05）. Coronary angiography showed that CTFC and TMPG of RR group were higher than those of control group（P 〈0.05）. Conclusion The changes of blood flow velocity and myocardial blood perfusion caused by vascular endothelial dysfunction may lead to RR of ^201TI myocardial imaging in patients with coronary heart disease. RR of myocardial perfusion imaging is valuable for the clinical diagnosis of infarcted vascular recanalization and segmented viable myocardium.