二维斑点追踪成像评价慢性心力衰竭患者左心室收缩不同步及其与收缩功能的关系

目的 应用二维斑点追踪成像(2D-STI)技术评价慢性心力衰竭(CHF)患者左室的收缩不同步特征,并探讨其与心衰程度的关系.方法 CHF组42例,其中CHF 1组19例,35%<左室射血分数(LVEF)≤50%;CHF 2组23例,LVEF≤35%;正常对照组35例.常规超声心动图双平面Simpson法测量LVEF;应用2D-STI测量自心电图QRS波起点至左室在心尖长轴观上的收缩期纵向应变率达峰时间(Tsrsl)及胸骨旁短轴观上的径向和环向应变率达峰时间(Tsrsr,Tsrsc).计算左室各节段达峰时间标准差(Tsrsl-SD,Tsrsr-SD,Tsrsc-SD)及任意两节段达峰时间最大差值(Tsrsl-diff,Tsrsr-diff,Tsrsc-diff)为判断收缩期不同步指标.结果 与对照组相比,CHF 1、CHF 2组左室收缩不同步指标Tsrsl-SD、Tsrsr-SD、Tsrsc-SD及Tsrsl-diff、Tsrsr-diff、Tsrse-diff均显著延长,差异具有统计学意义(P<0.05);与CHF1组比较,CHF 2组上述不同步指标均延长,差异具有统计学意义(P<0.05).CHF组收缩不同步指标与LVEF值相关分析:2D-STI收缩不同步指标Tssrl-SD、Tsrsr-SD、Tsrsc-SD与LVEF呈显著负相关(r=-0.904～0.912,均P<0.05),Tsrsl-diff、Tsrsr-diff、Tsrsc-diff与LVEF亦呈显著负相关(r=-0.916～0.967,均P<0.05),其中LVEF与2D-STI在径向和环向的不同步指标相关性大于纵向.结论 2D-STI可检测CHF左室收缩不同步性,心力衰竭程度越重,2D-STI不同步程度越重.

Assessment of left ventricular systolic asynchrony by two dimensional speckle-tracking imaging and its relationship with ejection fraction in patients with chronic heart failure

Objective To assess the characteristics of left ventricular(LV) systolic dyssynchrony in patients with chronic heart failure (CHF) using two dimensional speckle-tracking imaging(2D-STI) and validate the correlation between LV systolic dyssynchrony and its ejection fraction (EF) measured by traditional two dimensional echocardiography. Methods Forty-two patients with CHF, which were divided into group CHF1 with 35% ＜EF≤50% and group CHF2 with EF≤35%, and 35 healthy subjects as control group were enrolled in this study. Two-dimensional echocardiography Simpson's method was used to measure EF of LV. The time from the onset of QRS complexes to systole peak strain rate from the longitudinal, radial and circumferential vectors(Tsrsl, Tsrsr, Tsrsc)was recorded and measured using 2D-STI, respectively. The standard deviation and the maximal temporal difference of Tsrsl, Tsrsr, Tsrsc (Tsrsl-SD,Tsrsr-SD,Tsrsc-SD,Tsrsl-diff,Tsrsr-diff, Tsrsc-diff)of 18 segments were calculated as indicator of LV systolic dyssynchrony. Results The indices of LV systolic dyssynchrony Tsrsl-SD,Tsrsl-diff, Tsrsr-SD, Tsrsr-diff,Tsrsc-SD,Tsrsc-diff in group CHF1 and CHF2 were significantly higher than those in the control group (P<0.05). Compared with group CHF1, those indices in CHF2 were significantly longer (P<0.05). Meanwhile, Tsrsl-SD, Tsrsr-SD, Tsrsc-SD(r = - 0.904～0.912, all P<0.05) and Tsrsl-diff, Tsrsr-diff, Tsrsc-diff(r = - 0.916～0.967, all P<0.01) had singnificantly negative correlations with LVEF, and the correlation coefficients between radial and circumferential 2D-STI dyssynchrony parameters and LVEF were higher than those between the longitudinal parameters and LVEF. Conclusions 2D-STI is a useful modality to evaluate the LV systolic asynchrony of the CHF and there is a good correlation between LVEF and the LV systolic dyssynchrony indices derived from 2D-STI.