心肌声学造影对冠状动脉狭窄时微血管自动调节现象的研究

To evaluate the changes of the microcirculation of coronary artery at rest and during pharmacological stress in coronary artery disease (CAD). The regional % wall thickening (%WT), myocardial blood flow (MBF), myocardial blood volume (MBV) and myocardial microbubble velocity (VEL) were measured with echocardiography, myocardial contrast echocardiography (MCE) and radiolabeles microshperes. The new findings of our studies are these, in the presence of noncritical coronary stenoses, abnormalities in resting %WT as well as inducible reduction in %WT during pharmacological stress are related to the degree of abnormal MBF reserve. Except coronary "steal", a reduced endocardial MBF reserve is the primary mechanism of dipyridamole-induced regional dysfunction in chronic CAD. The effects of dipyridamole and dobutamine on MBV and VEL are different. These new findings provide additional insights into the complex pathophysiology of CAD and they have important bearing in the early and non-invasive evaluation of CAD.

应用静脉MCE定量心肌灌注技术，在急慢性冠脉狭窄犬模型上测定静息时和药物负荷时的CBF、CBV、MBF和MBV变化；对比MCE和放射微球测定心肌血流的关系；用MCE测定MBV的舒张末期和收缩末期比值，对比此比值与狭窄冠脉压力阶差、冠状窦血流及放射微球测定结果的关系。观察冠脉微血管对冠脉狭窄的适应性反应，探讨静息下诊断冠脉狭窄的可行性。