二维斑点追踪显像技术预测心脏再同步治疗的疗效

Longitudinal two dimensional strain rate imaging is superior to tissue Doppler imaging in predicting echocardiographic response in cardiac resynchronization therapy

目的旨在比较二维斑点追踪显像技术与现有的超声心动图技术对心脏再同步治疗（CRT）疗效的预测价值。方法施行CRT的患者50例，每个患者植入术前均采用血流多普勒、组织多普勒和二维斑点追踪显像的方法进行收缩不同步的评价，有效者定义为术后6个月左心室收缩末容积缩小〉15％或左心室射血分数（LVEF）绝对值增加〉5％的患者。结果CRT有效组起搏前左心室射血前时间显著长于无效组[（146．0±34．5）ms对（123．5±32．0）ms，P〈0．05]，其余常规超声心动图参数和组织多普勒参数在两组间差异无统计学意义。二维斑点追踪显像技术示CRT有效组和无效组的左心室应变达峰时间标准差（Tstrain—SD）的差异无统计学意义（P〉0．05），而CRT有效组的应变率结束时间标准差（Tsr—SD）显著高于无效组（P〈0．05）。两组间左心室应变均值（Strain-12）的差异亦无统计学意义（P〉0．05），而CRT有效组的左心室12节段纵轴反向应变总和（Pstrain-12）显著高于无效组[（12．5±7．9）％对（7．1±8．4）％，P〈0．05]。将140．5ms作为截点值，左心室射血前时间预测超声心动图有效的敏感性和特异性分别为63％和79％，将70．7ms作为截点值，Tsr—SD预测CRT有效的敏感性和特异性分别为73％和65％。结论常规超声心动图参数中仅左心室射血前时间能预测CRT疗效，二维斑点追踪显像技术的部分参数预测CRT疗效优于组织多普勒。

Objective The aim of this study was to investigate the ability of longitudinal strain and strain rate imaging by two dimensional speckle tracking in predicting echocardiographic response under cardiac resynchronization therapy （CRT） ,in comparison with tissue Doppler imaging （TDI）. Methods Fifty patients suffering from heart failure,who received CRT, were selected. TDI and two dimensional speckle tracking imaging in addition to standard echocardiography were performed prior to CRT. The average value of peak longitudinal strain in 12 left ventricular（ LV ） segments （Strain-12）, the standard deviation of time to peak longitudinal strain in 12 LV segments （Tstrain-SD） and the standard deviation of time to the end of longitudinal systolic strain rate in 6 basal LV segments （Tsr-SD） were calculated. Patients were classified as echocardiographic responders if the LV end-systolic volume （LVESV） was reduced 〉 15% compared with baseline volumes. Resuits No significant difference was seen in baseline Ts-SD, Strain-12 and Tstrain-SD between nonresponders and responders. However, the Tsr-SD was much higher in responders than nonresponders [ （95.9 ± 33.0） % vs （64. 8 ±39. 6） % , P 〈 0. 05 ） , and it showed a sensitivity of 73% and specificity of 65 % for the defined echocardiographic response using a cutoff value of 70. 7 ms. Conclusions Longitudinal two dimensional strain rate imaging is reproducible and could be used as a predictor of echocardiographic response after CRT.