分层应变评价兔急性心肌缺血早期左室收缩功能的改变-现代医学

分层应变评价兔急性心肌缺血早期左室收缩功能的改变

单位：南京医科大学附属常州第二人民医院心超室, 江苏常州 213003

分类号：R331.31;R-332

出版年·卷·期（页码）：2017·36·第十一期（1562-1568）

摘要：

目的：应用二维斑点追踪显像（2D-STI）分层应变技术评价急性心肌缺血早期左室整体和局部收缩功能。方法：对40只健康大白兔开胸行冠状动脉左室支结扎术建立急性心肌缺血模型，采用心脏超声诊断仪于术前、术后分别采集心尖四腔心、长轴、二腔心切面以及短轴二尖瓣水平、乳头肌水平、心尖水平切面二维动态图像。应用GE Echo PAC软件脱机分析左室整体应变及18节段的收缩期纵向、周向三层心肌（心内膜下心肌、中层心肌、心外膜下心肌）峰值应变。结果：对40只兔子进行长轴纵向应变分析；由于短轴图像质量原因，对成功追踪短轴切面的30只兔子进行周向应变分析。常规参数：兔术前、术后心率（HR）的差异有统计学意义（P<0.05），而室间隔厚度（IVST）、左室后壁厚度（LVPWT）、左室舒张末期内径（LVDd）、左房内径（LAD）、左室射血分数（LVEF）差异均无统计学意义（P>0.05）。整体应变：左室三层心肌整体纵向应变（GLS）、整体周向应变（GCS）及整体跨壁梯度ΔGLS、ΔGCS术后均显著低于术前（P<0.001）。左室GLS、GCS自心内膜下心肌至心外膜下心肌逐层递减（P<0.001）。长轴节段应变：左室侧壁、前间隔、前壁心内膜下心肌、中层心肌、心外膜下心肌纵向收缩期峰值应变术后均显著低于术前（P<0.05）。中间段及心尖段左室下、后壁心内膜下心肌、中层心肌、心外膜下心肌纵向收缩期峰值应变术后均显著低于术前（P<0.05）。基底段、中间段后间隔及基底段下、后壁三层心肌的纵向收缩期峰值应变术前、术后的差异无统计学意义（P>0.05），但术后低于术前。短轴节段应变：中间段左室前壁、侧壁、下壁心内膜下心肌及基底段前间隔、后间隔的心外膜下心肌的周向收缩期峰值应变术后均显著低于结扎前（P<0.05）。其余各节段三层心肌周向收缩期峰值应变的术前、术后的差异无统计学意义（P>0.05），但术后较结扎前有所下降。结论：2D-STI分层应变技术通过分析兔急性心肌缺血早期左室各节段的纵向、周向分层应变，能更加精确评价急性心肌缺血早期左室整体和局部收缩功能。

Objective:Using two-dimensional speckle tracking imaging(2D-STI) to analysis layer-specific strain of rabbits' left ventricular(LV) in the early stage of acute myocardial ischemia(AMI), which is to assess global and regional systolic function of LV. Methods:AMI model of forty white rabbits was established through ligating the left ventricular branch of coronary artery. Two-dimensional images were recorded and stored in apical four-chamber,long-axis,two-chamber and the short-axis view at the level of mitral valve,papillary muscle and apex. The highest value of longitudinal strain(LS),circumferential strain(CS),global longitudinal strain (GLS) and circumferential strain(GCS),using EchoPAC was respectively assessed from endocardium,mid-myocardium and epicardium of 18 sections. Results:AMI model of forty white rabbits was successfully established to conduct longitudinal strain analysis, and 30 rabbits to conduct circumferential strain analysis because 10rabbits were excluded due to quality control requirement. The difference in HR between preoperative and postoperative was significant, but tIVST,LVPWT,LVDd,LAD and LVEF was not. The difference in three-layer GLS, GCS, global gradient-longitudinal stain(ΔGLS) and global gradient-circumferential stain(ΔGCS) was significant(P<0.001) and the value was lower than the preoperative one. The values of GLS and GCS were the highest in endocardium and the lowest in the epicardium(P<0.001). The value of long-axisin endocardium,mid-myocardium and epicardium of left lateral,anterior and anterior septum wall all showed a great decrease(P<0.05).The value of LS inthree-layer of inferior,posterior wall of left middle and apex sections was decreased after the operation(P<0.05). The value of LS in three-layer of posterior septum of basal,middle segment and inferior,posterior of basal segment decreased, but there was no significant difference(P>0.05). The value of CS in endocardium of left anterior,lateral,inferior wall of middle section and epicardium of anterior septum,posterior septum of basal section all showed a great decrease, and there was a significant difference(P<0.05). The rest sections of CS in three-layer had no significant difference (P>0.05), but the value measured postoperatively was lower than the preoperative one. Conclusion:To analysis LS and CS layer-specific strain of rabbits' LV sections in the early stage of AMI using 2D-STI can assess global and regional systolic function of LV in detail.

参考文献：

[1] SU A K,PARK S M,KIM M N,et al.Assessment of left ventricular function by layer-specific strain and its relationship to structural remodeling in hypertensive patients[J].Can J Cardiol,2016,32(2):211-216.
[2] 李彦明,姜红,张正聪,等.兔心脏冠状动脉的解剖学观察[J].宁夏医科大学学报,2013,35(10):1099-1102.
[3] SAKURAI D,ASANUMA T,MASUDA K,et al.Myocardial layer-specific analysis of ischemic memory using speckle tracking echocardiography[J].Int J Cardiovasc Imaging,2014,30(4):739-748.
[4] 赵志玉,陈金玲,周青,等.心肌纵向分层应变参数评价冠心病患者左心室局部及整体收缩功能[J].中华超声影像学杂志,2016(1):1-6.
[5] SHI J,PAN C,KONG D,et al.Left ventricular longitudinal and circumferential layer-specific myocardial strains and their determinants in healthy subjects[J].Echocardiography,2015,33(4):510.
[6] 姜中慧,李克婷,田家玮,等.斑点追踪成像多层分析技术评价兔心肌缺血药物后适应模型左心室纵向心肌功能变化[J].中华超声影像学杂志,2017,26(1):65-70.
[7] CAMELLITI P,BORG T K,KOHL P.Structural and functional characterisation of cardiac fibroblasts[J].Cardiovasc Res,2005,65(1):40.
[8] LIU Y J,LENG X P,DU G Q,et al.Two-dimensional longitudinal strains and torsion analysis to assess the protective effects of ischemic postconditioning on myocardial function:a speckle tracking echocardiography study in rabbits[J].Ultrasonics,2015,56:344.
[9] GONG L,LI D,CHEN J,et al.Assessment of myocardial viability in patients with acute myocardial infarction by two-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography[J].Int J Cardiovasc Imaging,2013,29(5):1017-1028.
[10] ALTIOK E,NEIZEL M,TIEMANN S,et al.Quantitative analysis of endocardial and epicardial left ventricular myocardial deformation-comparison of strain-encoded cardiac magnetic resonance imaging with two-dimensional speckle-tracking echocardiography[J].J Am Soc Echocardiogr,2012,25(11):1179.
[11] ISHIZU T,SEO Y,BABA M,et al.Impaired subendocardial wall thickening and post-systolic shortening are signs of critical myocardial ischemia in patients with flow-limiting coronary stenosis[J].Circ J,2011,75(8):1934-1941.

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