定量组织速度成像技术对左束支传导阻滞患者左心室运动非同步性的研究

Study of left ventricular asynchrony in patients with LBBB by quantitative tissue velocity imaging

目的应用定量组织速度成像(QTVI)技术研究左束支传导阻滞患者左心室运动的不同步性。方法选取30例完全性左束支传导阻滞(LBBB)患者和30例正常人。应用QTVI技术在标准心尖四腔、两腔及心尖左室长轴切面获得左心室18节段的速度时间曲线,测量达收缩期峰值速度时间(TS)、达舒张早期峰值速度的时间(TE)以及TS、TE标准差(TS-SD、TE-SD);计算18节段TS、TE最大差值(max-ΔTS、max-ΔTE)、同一壁各节段TS、TE最大差值(同一壁-ΔTS、同一壁-ΔTE)及同节段各壁TS、TE最大差值(同节段-ΔTS、同节段-ΔTE)。结果LBBB组max-ΔTS、max-ΔTE、同一壁-ΔTS、同一壁-ΔTE、同节段-ΔTS、同节段-ΔTE较正常对照组均明显延长。QRS间期与TS-SD、TE-SD无相关性。结论LBBB时左心室运动存在明显的不同步性,QTVI技术在评价LBBB心室运动不同步性方面具有无创、简捷、准确、可重复性好的特点。

Objective To assess left ventricular asynchrony in patients with left bundle branch block （LBBB） by quantitative tissue velocity imaging （QTVI）. Methods 30 patients with LBBB and 30 normal controls were studied by QTVI. The regional velocity curve of 18 segments of left ventricular four -chamber view, apical two- chamber view and apical long- axis view were obtained. The time to peak myocardial systolic contraction （ TS ） and early diastolic relaxation （ TE ） were measured. The standard deviation of TS （TS -SD） and of TE （TE -SD） was calculated. The maximal difference in TS and TE within all 18 segments （ max - △TS, max - △TE ）, the same wall （ same wall - △TS, same wall - △TE ）, and the same segment （ same segment - △TS and same segment - △TE） was calculated. Results TS, TE, max - △TS, max - △TE, same wall - △TS, same wall - △TE, same segment - △TS and same segment - △TE in patients with LBBB were significantly prolonged. QRS duration was not correlated with TS - SD and TE - SD. Conclusion Asynchrony is conspicuous in the left ventricular in patients with LBBB. QTVI is a rapid, non- invasive, and quantitative method for assessing left ventricular asynchrony in patients with LBBB.