急性冠脉闭塞犬心肌内血流改变的多普勒显像研究

目的应用冠脉血流多普勒显像技术观察急性前降支冠脉闭塞后后壁心肌内血流改变，并探讨这种变化的意义。方法15条杂种犬常规麻醉开胸后，应用冠脉血流程序观察前降支结扎后后壁内的血流信号改变，测量冠脉结扎前后后壁内血流速度，计算结扎后峰值血流速度和速度时间积分的变化值与结扎前相应指标之比；自主动脉根部注射Albunex进行心肌声学造影显像，观察前壁内造影效果，并进行造影评分，测量充填缺损区面积。结果根据前壁内显影效果，将实验犬分为A、B两组A组5条，前降支冠脉结扎后声学造影时前壁内完全未见造影剂充填，造影评分为0分；B组9条，声学造影时前壁内有不同程度的造影增强，评分为1或2分。A组结扎后后壁峰值血流速度变化分数(V2－V1)/V1]和速度时间积分变化分数(VTI2－VTI1)/VTI1]明显低于B组，差异有显著性意义A、B两组(V2－V1)/V1分别为0.068±0.100和0.690±0.460，P＜0.01；(VTI2－VTI1)/VTI1分别为0.123±0.197和0.990±0.770，P＜0.01]。冠脉结扎后，两组前壁增厚率和左室射血分数均较结扎前明显降低，A、B两组各相对应参数间差异无显著性(P均＞0.05)。结论冠脉血流显像技术不但能发现冠脉结扎后靶血管供血区心肌内血流变化，而且可观察对侧心肌内血流的改变，在缺血区有侧支血流供应组(B组)对侧后壁内血流增加，通过对侧心肌内血流速度的变化，能间接判断侧支循环的开放情况。

Assessment of Intramyocardial Flow Changes after Acute Coronary Occlusion by Coronary Flow Doppler Imaging

Objective To observe the contralateral intramyocardial flow change by coronary flow Doppler imaging (CFDI) and to evaluate the significance of such change in the assessment of coronary collateral recruitment after coronary occlusion. Methods 15 anaesthesized open chest mongrel dogs were examined with CFDI to observe the intramyocardial flow change in the posterior wall. The flow velocity and flow integral were measured and then calculated the change fraction. Myocardial contrast echocardiography (MCE) was made after infusion of Albunex through the aortic root. Then the contrast effect was evaluated and scored. Results A dog died of ventricular fibrilliation. According to the contrast enhancement effect, 14 dogs were divided into 2 groups: group A consisted of 5 dogs without any contrast enhancement ( score: 0) by MCE; group B included 9 dogs with contrast enhancement at different degree. The anterior wall thickening fraction and left ventricular ejection fraction were worsened after occlusion in the 2 groups. But there were no difference of the two indices between the 2 groups. Conclusion The intramyocardial flow change could be found in the contralateral myocardium by coronary flow Doppler imaging. The flow change was related with collateral recruitment.