速度向量成像评价DDD起搏前后左心室收缩同步性的初步临床研究

目的 探讨速度向量成像(velocity vector imaging,VVI)技术评估DDD起搏前后左心室心肌收缩同步性的应用价值.方法 13例DDD起搏患者,于手术前后应用VVI在系列心尖长轴及胸骨旁短轴观上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)和纵向应变达峰时间(Tsl),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),并计算节段达峰时间的标准差(Tvl-SD,Tsl-SD,Tvr-SD,Tsc-SD)及任意两节段间最大达峰时间差值(Tvl-d,Tsl-d,Tvrd,Tsc-d).结果 与术前相比,术后左室收缩不同步指标Tvr-SD,Tsc-SD,Tsl-d,Tvr-d,Tsc-d均显著增加,差异有统计学意义(P＜0.05).结论 DDD起搏后左室心肌在纵向、径向和环向上均存在显著的收缩不同步.VVI技术可准确评价DDD起搏前后左室心肌收缩的同步性.

Assessment of left ventricular systolic synchrony in patients with DDD pacing by velocity vector imaging

Objective To assess the left ventricular(LV)contraction synchrony in patients with DDD pacing by velocity vector imaging(VVI).Methods Acoustic clip capture was performed in 13 patients before and after pacemaker implantation and obtained high-frame rate B-mode echocardiographic images.VVI was done in all three standard LV apical views and parasternal LV short axis(SAX)views.The time to peak systolic longitudinal velocity(Tvl)and systolic longitudinal strain(Ts1)in the LV apical views and the time to peak systolic radial velocity(Tvr)and systolic circumferential strain(Tsc)in the LV SAX views were measured bv VVI.The standard deviation of Tvl,Tsl,Tvr and Tsc(Tvl-SD,Tsl-SD,Tvr-SD and TscSD)and the maximal temporal difference of Tvl,Tsl,Tvr and Tsc(Tvl-d,Tsl-d,Tvr-d and Tsc-d)of 18 segments were calculated.Results Compared with the values at baseline,Tvr-SD,Tsc-SD,Tsl-d,Tvr-d and Tsc-d increased significantly in patients after pacemaker implantation(P＜0.05).Conclusions The longitudinal,radial and circumferential systolic asynchrony of the LV was commonly existed in patients after DDD pacing.VVI can be used to evaluate the systolic synchrony of the LV in patients with DDD pacing.