超声二次谐波心肌声学造影评价冠脉的微血管血流灌注

Coronary micro-vascular perfusion evaluated by second harmonic myocardial contrast echocardiography with intravenous injection of microbubbles

目的:本文获取冠状动脉血流变化所致的心肌灌注类型,以了解冠脉的微血管血流灌注变化。方法:36人先后完成冠状动脉造影,静脉注射声学造影剂利声显（Levovist）,通过超声二次谐波技术获取心肌灌注图像,按心肌灌注积分指数将病人分为三组。结果:三组病人的冠状动脉狭窄程度、心肌灌注积分指数明显差异（P<0.001）,冠状动脉狭窄度<75％者,病人心肌灌注多为正常,随着冠状动脉狭窄程度加重,出现不同程度的心肌灌注异常。8例完全阻塞的冠状动脉有不同的冠状动脉侧支循环表现为不同的心肌灌注类型。结论:静脉心肌声学造影是反映心肌灌注的有效方法,能够反应冠状动脉血流的改变及微循环结构的完整性变化,从而弥补冠状动脉造影仅能显示心外膜下的冠状动脉而无法观察毛细血管水平的心肌灌注之缺限。当心肌灌注不良时,MCE能提示冠状动脉病变的存在,及其严重性,但要注意侧支循环对心肌灌注之影响,可影响对冠脉病变程度判断的精确性。冠状动脉造影确定某支冠脉病变时,MCE心肌灌注有助于评价侧支循环状态。

Objective: This study assess the different pattern of coronary micro-vascular perfusion estimated by myocardial per-fusion using second harmonic myocardial contrast echocardiography by injecting leviosl from venous. Methods: 36 individuals underwent coronary artery angiography and myocardial contrast echocardiography(MCE) . The diseased arteries were Classified as three groups according to the perfusion score. Results: There were significant difference between the myocardial perfusion score index and coronary artery stenosis rate among three groups.when coronary stenosis were less than 75%,the myocardial perfusion was normal,but when coronary stenosis increased,myocardial perfusion become abnormal.There are 8 total occluded arteries, the myocardial perfusion were different because of different collateral circulation. Conclusions: MCE was an effective method for detecting myocardial perfusion which showed the different coronary perfusion and the integrity of coronary micro-vascular structure. So it aid to detect the myocardial perfusion supplied by microvascular perfusion which could not showed by coronary angiography. When myocardial perfusion was damaged, MCE can suggest coronary artery disease and its severity, but one should be careful about coronary colleteral circulation, this may affect the accuracy of estimating coronary artery disease. When coronary artery angiography showed diseased coronary artery, MCE could be used to evaluate the collateral circulation.