心肌声学造影估测冠脉血流储备及心内膜下心肌灌注的实验研究

Experimental Study of Assessing Coronary Blood Flow Reserve and Subendocardial Perfusion by MCE

目的 :探讨心肌声学造影定量冠脉血流储备及心内膜下心肌灌注的意义。材料与方法 :13只开胸犬左旋支临界狭窄状态及静脉注射潘生丁后分别进行心肌声学造影并与放射性微球所测心肌血流量对比。结果 :静注潘生丁后 ,正常对照区心肌血流量及心肌造影曲线下面积、峰值强度、最大上升斜率指标均明显增加 ;而临界狭窄缺血区无明显变化。在临界狭窄缺血区 ,放射性微球所测的心内膜下 /心外膜下心肌血流比率减低 ;但以造影曲线下面积指标所测则无明显变化。结论 :心肌声学造影曲线下面积、峰值强度及最大上升斜率是定量评价冠脉血流储备的可靠指标 ;

Purpose: This study was designed to investigate the value of myocardial contrast echocardiography (MCE) for measuring the coronary blood flow reserve and subendocardial perfusion. Materials and Mathods: In thirteen open chest dogs with a critical stenosis in the left circumflex coronary, measurements of contrast time intensity curve were made along each segment, the results were compaired with regional myocardial flow determined by rdiolabled microspheres. Results: After dipyridamole, the transmural flow by rdiolabled microspheres and the area under the curve、peak intensity maximum appcarance slop increased sigificantly in the control region. In the ischemic region, there wase no significantly changes. The ratio of subendocardial to subepicardial flow measured by microspheres decreased significantly after dipyridamole administration in the ischemic region, but the ratio by area under the curve were not significantly changed. Conclusions: Area under the curve、peak intensity、maximum appearance slope are good parameters depicting coronary flow reserve. The subendocardial perfusion precludes evaluting by MCE becauseof current limited technique.