超声斑点跟踪技术评价扩张性心肌病患者左室整体收缩功能的临床研究

目的 应用超声斑点追踪技术(STI)评价扩张性心肌病患者(DCM)的左室心肌力学特性,探讨测定二尖瓣环位移(MAD)评价左室收缩功能的可行性.方法 应用STI技术测定DCM患者和正常对照组左室整体纵向应变(GLs)、径向应变(GRs)、圆周应变(GCs)、左室扭转(LVtw)和MAD,应用实时三维超声心动图测定左室射血分数(LVEF),分析心肌应变和扭转参数与MAD和LVEF之间的关系.结果 与对照组比较,DCM患者各参数减低(P<0.01),纵向应变在整体功能上的作用减弱(beta值0.66 vs 0.54,P<0.01),周向应变作用加强(beta值0.38 vs 0.44,P<0.01);DCM组GLs及LVtw是TMAD的独立预测因子;如果设定MAD为8.9 mm时,其诊断LVEF≤50%的敏感性为100%,特异性为95%.结论 MAD和LVEF之间存在良好的相关性,有望成为临床常规评价DCM患者左室整体功能的一种快捷、准确的新方法.

Assessment of Global Systolic Function of Left Ventricle in Patients with Dilated Cardiomyopathy by Two-dimensional Speckle Tracking Imaging

Objective To evaluate the myocardial systolic features of the left ventricle(LV)by speckle tracking imaging(STI)in patients with dilated cardiomyopathy(DCM)in order to determine the feasibility of evaluation of LV funtion with mitral annular displacement(MAD).Methods The systolis parameters including longitudinal strain(GLs),radial strain(GRs),circumferential strain(GCs),LV twist(LVtw)and MAD were obtained using STI and LVEF was acquired by three dimensional echocardiography in control group and DCM group,and the correlation between these parameters and MAD as well as LVEF was analyzed respectively.Results The parameters in DCM group were significantly lower than those in the healthy subjects(P<0.01),and the contribution of GLs was attenuated(beta value 0.66 vs 0.54,P<0.01)while the contribution of GCs was enhanced(beta value 0.38 vs 0.44,P<0.01).GLs and LVtw were the independent predictors of MAD in DCM group.The cut-off value of MAD for LVEF≤50% was 8.9 mm with a sensitivity of 100% and a specificity of 95%.Conclusions MAD may be a new promising modality to evaluate the global systolic function of left ventricle for clinical routine practice.