Recovery of Myocardial Perfusion and Left Ventricular Wall Motion Abnormality after Recanalization of Obstructed Coronary Artery

本研究的目的是揭示阻塞冠状动脉再通后心肌灌注的恢复与局部室壁运动异常的关系。心肌声学造影评价心肌灌注。通过导管注入造影剂对冠状动脉床进行染色。根据感兴趣区的时间强度曲线计算对比剂的峰值强度和洗脱率。在犬模型中，再通后不久冠状动脉流量显著增加。然而，造影剂从再灌注区的洗脱速率延迟。洗脱率与冠脉流量增加呈负相关。这表明造影剂的洗脱率越差，反应性充血的增量越小。此外，在造影剂洗脱率延迟的病例中，观察到室壁运动异常延迟恢复。心肌微循环障碍越明显，异常运动恢复越慢。在临床研究中，对心肌梗塞患者进行了心肌声学造影与201-铊心肌显像的对比研究。超声心动图也显示室壁运动异常。大部分患者的心肌灌注超声造影与核医学评价结果一致。然而，在一些患者中，通过铊造影术评估的灌注缺损区域被造影剂回声描记术染色。这个节段起初表现出运动，但几个月后变得运动减退。结果表明，RI与超声心动图评价心肌灌注的差异有临床意义。

The aim of this study is to reveal the recovery of myocardial perfusion after recanalization of obstructed coronary artery with reference to regional wall motion abnormalities. Myocardial contrast echocardiography was used to assess the myocardial perfusion. The coronary bed was stained by injected contrast agents through a catheter. Peak intensity and washout rate of contrast were calculated from time intensity curve in the area of interest. In the canine model, the coronary flow increased significantly soon after recanalization. However, the washout rate of contrast from the reperfused area was delayed. The washout rate was correlated inversely with the increment of coronary flow. This indicates that the worse the washout rate of contrast, the smaller the increment of reactive hyperemia. Also, delayed recovery of the wall motion abnormality was noted in cases with delayed washout rate of contrast. The more significant the microcirculation of myocardium was impared, the slower the abnormal motion was recovenred. In the clinical study, the data of myocardial contrast echocardiography was compared with those of 201-Thallium myocardial scintigraphy in patients with myocardial infaction. Wall motion abnormalities were also by echocardiography. The evaluation of myocardial perfusion was correspondent well between contrast echo and nuclear medicine in most patients. In some patients, however, the perfusion defect area assessed by Thallium scintigraphy was stained by contrast echography. This segment had shown a kinesis at first, but became hypokinetic after months. It is revealed that the difference of the evaluation of myocardial perfusion assessed by RI and echo is clinically significant.