实时三维斑点追踪成像评价不同程度冠状动脉狭窄左心室局部舒张功能

Assessment of Left Ventricular Regional Diastolic Function in Different Degrees of Coronary Stenosis by Three-dimensional Speckle Tracking Imaging

目的应用实时三维斑点追踪成像（RT3D-STI）技术对无节段性室壁运动异常的冠心病患者左心室局部舒张功能进行研究,探讨RT3D-STI诊断早期冠心病的价值。资料与方法疑诊为冠心病的140例患者共420支冠状动脉主要分支,根据冠状动脉造影结果分为无冠状动脉狭窄组101支、轻度冠状动脉狭窄组（冠状动脉狭窄〈50%）112支、中度冠状动脉狭窄组（冠状动脉狭窄50%~75%）95支、重度冠状动脉狭窄组（冠状动脉狭窄〉75%）112支。经胸采集三维全容积图像,计算各方向应变显像舒张指数（SI-DI）,分析其对冠心病的诊断价值。结果轻度冠状动脉狭窄组面积SI-DI、纵向SI-DI、径向SI-DI均低于无冠状动脉狭窄组（P〈0.05）;中度冠状动脉狭窄组纵向SI-DI、面积SI-DI、径向SI-DI及圆周SI-DI均低于无冠状动脉狭窄组（P〈0.05）,面积SI-DI、纵向SI-DI及圆周SI-DI均低于轻度冠状动脉狭窄组（P〈0.05）;重度冠状动脉狭窄组纵向SI-DI、面积SI-DI、径向SI-DI及圆周SI-DI均低于无冠状动脉狭窄组及轻度冠状动脉狭窄组（P〈0.05）,面积SI-DI、纵向SI-DI、径向SI-DI均低于中度冠状动脉狭窄组（P〈0.05）。ROC曲线显示纵向SI-DI的灵敏度最高,为84.0%;面积SI-DI的特异度最高,为78.9%。结论 RT3D-STI对早期发现及诊断冠心病有重要意义,冠状动脉供血区局部舒张功能减低早于收缩功能减低,舒张功能对心肌缺血更敏感,SI-DI可以在一定程度上反映冠状动脉的狭窄程度。

Purpose To evaluate the left ventricular regional diastolic function in coronary heart disease（CHD） patients without regional wall motion abnormality by real-time three-dimensional speckle tracking imaging（RT3D-STI） to investigate the value of RT3D-STI in the diagnosis of early CHD. Materials and Methods 140 CHD patients with 420 coronary artery main branches were enrolled and divided into 4 groups according to the results of coronary angiography（CAG）： normal group（101 coronary artery branches without stenosis）, mild stenosis group（112 coronary artery branches with stenosis50%）, moderate stenosis group（95 coronary artery branches with stenosis 50%-75%） and sever stenosis group（112 coronary artery branches with stenosis75%）. Three dimensional full volume images were collected through the chest, and the corresponding strain imaging diastolic index（SI-DI） of each direction was calculated, their value for the diagnosis of coronary artery disease was analyzed. Results The longitudinal, area and radial SI-DI of mild coronary artery stenosis group were lower than those of normal group（P〈0.05）; the longitudinal, area, radial and circumferential SI-DI of moderate coronary artery stenosis group were lower than normal group（P〈0.05） and the area, longitudinal and circumferential SI-DI were lower than those of the mild stenosis group（P〈0.05）; the longitudinal, area, radial and circumferential SI-DI were all lower than those of normal and mild stenosis group（P〈0.05）, and the area, longitudinal and radial SI-DI were all lower than the moderate stenosis group（P〈0.05）. ROC curve showed that the sensitivity of longitudinal SI-DI（84.0%） was highest, while the specificity of area SI-DI（78.9%） was the highest. Conclusion RT3D-STI has important significance for early detection and diagnosis of CHD, regional diastolic function decrease of the coronary artery supply area occurs earlier than systolic function reduction, and diastolic function is more sensitive for myocardial ischemia, as a result, SI-DI is able to reflect the stenosis degree of coronary artery in a certain extent.