速度向量成像评价左束支传导阻滞患者左心室收缩同步性

目的探讨速度向量成像（VVI）技术评估左束支传导阻滞（LBBB）患者左室心肌收缩同步性的临床应用价值。方法LBBB患者15例和健康志愿者30例,常规测量左室舒张末期内径（LVDd）、收缩末期内径（LVDs）、舒张末期容积（LVEDV）、收缩末期容积（LVESV）和射血分数（LVEF）。在系列心尖长轴及胸骨旁短轴观上,VVI成像显示左室速度向量图。心尖长轴观测量各节段收缩期纵向速度达峰时间（Tvl）,胸骨旁短轴观测量收缩期径向速度达峰时间（Tvr）和环向应变达峰时间（Tsc）,计算上述各达峰时间的标准差（Tvl-SD,Tvr-SD,Tsc-SD）及任意两节段间最大达峰时间差值（Tvl-diff,Tvr-diff,Tsc-diff）。结果①与对照组相比,LBBB组LVESV显著增加（P〈0.05）,LVEF显著降低（P〈0.05）,而LVDd、LVDs、LVEDV测值两组间比较差异无统计学意义。②LBBB组各节段Tvl、Tvr、Tsc测值及Tvl-SD、Tvr-SD、Tsc-SD、Tvl-diff、Tvr-diff、Tsc-diff测值均显著高于对照组的相应测值（P〈0.05或0.01）。③LBBB组前间隔心尖段Tvr测值最小,左室侧壁心尖段Tvr测值最大,两者间比较差异有统计学意义（P〈0.01）。结论LBBB患者左室心肌在纵向、径向与环向上均存在显著的收缩不同步。VVI技术为评价LBBB患者左室心肌收缩同步性,观察左室心肌收缩序列异常提供了一种新的方法。

Assessment of left ventricular contraction synchrony in patients with left bundle branch block using velocity vector imaging

Objective To assess the contraction synchrony of the left ventricle (LV) in patients with left bundle branch block (LBBB) using velocity vector imaging(VVI).Methods Fifteen patients with LBBB (LBBB group) and 30 healthy subjects (control group) were enrolled in this study.Left ventricular end-diastolic dimension (LVDd),end-systolic dimension (LVSd),end-systolic volume (ESV),end-diastolic volume (EDV) and ejection fraction (LVEF) were measured using two-dimension echocardiography.VVI examinations were conducted in the standard LV apical views and the parasternal short axis (SAX) views.According to 16 segments analysis method,the time to peak systolic longitudinal velocity (Tvl) was derived from the LV apical views,the time to peak systolic radial velocity (Tvr) and to peak systolic circumferential strain (Tsc) were derived from the LV SAX views.The standard deviation of Tvl,Tvr and Tsc (Tvl-SD,Tvr-SD and Tsc-SD) and the maximal temporal difference of Tvl,Tvr and Tsc (Tvl-diff,Tvr-diff and Tsc-diff) of 16 segments were used as an indicator of contraction dyssynchrony of LV.Results Compared with the values in the control group,the ESV increased and the LVEF decreased significantly (P<0.05) in the LBBB group.The values of Tvl,Tvr and Tsc in all of the segments and Tvl-SD,Tvr-SD,Tsc-SD,Tvl-diff,Tvr-diff and Tsc-diff were significantly higher in the LBBB group than those in the control group (P<0.05 or 0.01).The shortest and the longest Tvl,Tvr and Tsc were measured in the anteroseptal and lateral segments of LV respectively.Conclusions The longitudinal,radial and circumferential contraction dyssynchrony of the LV was commonly existed in patients with LBBB.VVI is a useful tool to evaluate the contraction synchrony of LV in patients with LBBB.