三维斑点追踪超声心动图对肥厚型心肌病患者左心室心肌力学研究

目的应用三维斑点追踪超声心动图(three-dimensional speckle tracking echocardiographic,3DSTE)分析肥厚型心肌病(hypertrophic cardiomyopathy,HCM)患者左心室(left ventricular,LV)整体和节段应变及应变率,评价3D STE在HCM患者左室心肌力学变化方面的临床应用价值。方法获得30例肥厚型心肌病患者(HCM组)和28例健康对照者(对照组)超声左室三维全容积动态图像并存储,应用3DSTE在机分析软件进行分析,获取左室的收缩末期容积指数(left ventricular end systolic volume index,LVESVI)、舒张末期容积指数(left ventricular end diastolic volume index,LVEDVI)、左室质量指数(left ventricular mass index,LVMI)、射血分数(left ventricula ejection fraction,LVEF)、左室整体和16节段收缩期纵向、径向及周向应变及应变率峰值,比较这些参数在两组间的差异。分析HCM组整体应变及应变率与节段室壁厚度的相关性。绘制左室整体收缩期三维、纵向、径向及周向应变及应变率峰值(left ventricle global 3Dstrain,LVG3DS)(left ventricle global longitudinal strain,LVGLS)(left ventricle global radial strain,LVGRS)(left ventricle global circumferential strain,LVGCS)(left ventricle global circumferential strain rate,LVGCSR)受试者工作特征曲线(receiver operating characteristic curve,简称ROC曲线),分析参数的敏感性和特异性。结果 HCM组LVESVI和LVEDVI明显低于对照组,LVMI明显高于对照组,差异均有统计学意义(P<0.05);LVEF差异无统计学意义(P>0.05);HCM组与对照组比较,左室整体应变及应变率、大部分节段应变及应变率均明显降低(P<0.05);HCM组左室整体应变及应变率与大多数节段室壁厚度呈显著负相关(P<0.05);ROC曲线显示LVG3DS诊断HCM的曲线下面积(The area under receiver operating characteristics,AUC)最大,约80.4%,当LVG3DS截断值为22.53时,敏感性最高约100.0%,约登指数0.615;当LVGRS和LVGCSR截断值分别为20.66和1.055时,两者特异性最高约95.0%,约登指数0.694。结论 HCM患者左室心肌整体及节段性收缩应变及应变率均降低,表明出现早期亚临床心肌功能受损,且室壁越厚,收缩功能受损越严重;在应用3DSTE诊断肥厚性心肌病的各项指标中,LVG3DS敏感度最高,LVGRS和LVGCSR特异度最高,说明3DSTE能敏感地分析心肌的力学变化,将具有较好的临床应用前景。

Left ventricular strain in hypertrophic cardiomyopathy assessed by three-dimensional speckle tracking echocardiography

Objective The aim of this study was to evaluate the capacity of three-dimensional speckle tracking echocardiographic （3D STE） strain parameters in the assessment of left ventricular （LV） systolic function in patients with hypertrophic cardiomyopathy （HCM）.Methods Thirty patients with HCM and 28 healthy subjects were examined for 3D STE analysis.The real-time 3D datasets were obtained and analyzed to derive the LV global and segmental longitudinal,radial and circumferential strains,as well as LV end systolic volume index（LVESVI） and end diastolic volume index （LVEDVI）,LV mass index（LVMI） and LV ejection fraction（LVEF）.The values of each 3D STE indexes were compared between the HCM and healthy group,and 3D STE global strain parameters were correlated with LV regional wall thickness in HCM.Draw receiver operating characteristic curves（ROC curves） on the LV global 3D,longitudinal,radial,circumferential strains and circumferential strain rate（LVG3DS） （LVGLS）（LVGRS） （LVGCS） （LVGCSR）,and analysis of sensitivity and specificity.Results Compared with healthy group,HCM has lower LVESVI and LVESVI,but higher lLVMI （both P＜0.05）.LV global strain and strain rate,most segmental strains and strain rates were significantly lower in HCM than in healthy group（P＜0.05） ; The LV global strain and strain rate showed a significant negative correlation with the LV wall thickness in most segments in HCM（P＜0.05）.The area under receiver operating characteristics （AUC） curve of LVG3DS to diagnose HCM was 80.4 ％.The cutoff value,the sensitivity and Youden index of LVG3DS were 22.53,80.4％ and 0.615.The cutoff value,the specificity and Youden index of LVGRS were 20.66,95.0％ and 0.694.The cutoff value,the specificity and Youden index of LVGCSR were 1.055,95.0％ and 0.694.Conclusion The decreased LV global and regional strains indicate the impaired LV systolic function in patients with HCM.LVG3DS is the most sensitive,LVGRS and LVGCSR are the most specific in all the strain parameters.3D STE has the potential for accurate and sensitive assessment of myocardial mechanics,and providing a relatively simple approach to assess LV function precisely in future.