基于斑点追踪测量二尖瓣环位移法的心肌顿抑犬左心室整体收缩功能的评价

Evaluation of left ventricular global systolic function with two- dimensional speckle tracking imaging in stunned myocardium of beagle dogs

目的应用斑点追踪测量二尖瓣环位移(MAD)法评价心肌顿抑犬左心室整体收缩功能的延迟变化。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,分为长顿抑组(阻断45 min)、短顿抑组(阻断15 min)和假手术组(不阻断),对阻断前,再灌注即刻,再灌注后10、30、60、90 min的二尖瓣环位移参数进行比较。结果再灌注即刻,长顿抑组的EMAD1、EMAD2、EMADm及EMADm%值均低于结扎前及假手术组,差异有统计学意义;短顿抑组的EMAD2、EMADm及EMADm%值均低于结扎前及假手术组,差异有统计学意义。再灌注后90min时长顿抑组EMAD1值低于短顿抑组,差异有统计学意义。结论应用斑点追踪测量MAD法可准确、便捷评价心肌顿抑犬左心室整体收缩功能的延迟变化。

Objective To investigative delayed relaxation of left ventricle globe systolic function in stunned myocardium by detection of mitral annular displacement（ MAD） with two- dimensional speckle tracking imaging. Methods Eighteen open- chest beagle dogs were divided into 3 groups： short time stunned group,long time stunned group and sham operation group. The acute myocardium ischemia was induced by ligating left anterior descending coronary artery for15（ short time stunned group） or 45（ long time stunned group） min. Two- dimensional imaging were obtained at the apical four- chamber view before ischemia,and 15 min and 45 min after ischemia,as well as 10,30,60 and 90 min after reperfusion. The parameters of MAD were obtained use off- line QLAB software. Results Compared with baseline and with sham operation group,EMAD1,EMAD2,EMADm and EMADm% in long time stunned group were significantly reduced. Compared with baseline and with sham operation group,EMAD2,EMADm and EMADm% in short time stunned group were also significantly reduced. Compared with short time stunned group,EMAD1 in long time stunned group at the90 min of reperfusion was significantly reduced. Conclusion Based on two- dimensional speckle tracking imaging,MAD is an accurate and rapid method determining delayed relaxation of LV global systolic function in stunned myocardium.