基于斑点追踪法的二尖瓣环位移参数与Tei指数评价顿抑心肌犬左室功能的相关分析

Analysis of correlation between mitral annular displacement based on speckle tracking imaging and Tei index in evaluation of left ventricular global systolic function of stunned myocardium of beagle dogs

目的评价顿抑心肌犬二尖瓣环位移(MAD)参数与左室Tei指数的相关性。方法制作冠状动脉左前降支阻断后再灌注犬心肌顿抑模型,分为顿抑组(阻断45 min)和假手术组(不阻断),M型超声测量左室舒张末内径(LVEDD)、左室收缩末内径(LVESD)以及左室射血分数(LVEF);于再灌注30 min采集心尖长轴观动态图像,将图像输入QLAB8.0工作站,分别获得EMAD1、EMAD2、EMADm及EMADm%参数;组织多普勒速度脉冲显像模式下,获得侧壁二尖瓣环运动频谱,并计算Tei指数。实验结束后,心肌标本行透射电镜检查,分析二尖瓣位移参数与Tei指数的相关性。结果顿抑组EMAD1、EMAD2、EMADm及EMADm%值均低于假手术组(P均<0.01),二尖瓣环位移参数与Tei指数呈负相关(P<0.01),EMADm%与Tei指数相关系数最高。结论二尖瓣环位移参数能客观评价犬顿抑心肌的左室收缩功能,与Tei指数密切相关,两者联合应用可全面评价顿抑心肌犬左室整体功能。

Objective It is to evaluate the correlation between mitral annular displacement and Tei index in evaluation of stunned myocardium of beagle dogs. Methods Several left anterior descending coronary artery occlusion and reperfusion models of myocardial stunning of beagle dogs were made,and they were assigned into stunned group（ blocking for 45min） and sham operation group（ without blocking）. Left ventricular end-diastolic diameter（ LVEDD）,left ventricular end-systolic diameter（ LVESD） and left ventricular ejection fraction（ LVEF） were measured by M- mode echocardiography. Apical long-axis view of a moving images were obtained after 30 min of reperfusion,and the images were input into QLAB8. 0 workstation. Thus the parameters,such as EMAD1,EMAD2,EMADm and EMADm% were acquired. Mitral annulus of lateral wall motion frequency spectrum derived from pulse wave Tissue Doppler imaging（ PW DTI） was used to obtain Tei Index. After experiment the myocardium specimens were examined by transmission electron microscopy. The correlation between mitral annular displacement and Tei index were analyzed. Results The value of EMAD1,EMAD2,EMADm and EMADm% in stunned group were lower than those in sham operation group（ P〈0. 01）. Mitral annular displacement were negatively correlated with Tei index（ P〈0. 01）,and there was a highest correlation coefficient between EMADm% and Tei index. Conclusion Mitral annular displacement parameters can evaluate left ventricular global function of stunned myocardium of beagle dogs objectively,and it is closely related to Tei index. The combination of the two indexes can give a comprehensive evaluation of left ventricular global function of stunned myocardium of beagle dogs.