速度向量成像技术评价DDD起搏前后左心室心肌应变与位移

Assessment of longitudinal segmental myocardial strain and displacement of left ventricle in patients with dual chamber pacing by velocity vector imaging

目的探讨速度向量成像(VVI)技术分析DDD起搏前后左心室心肌运动应变和位移变化规律以及该技术的应用价值。方法 23例DDD起搏患者手术前后均采用VVI技术检测心室各节段心肌收缩期纵向运动应变和位移,并比较其在手术前后的差异。结果 23例DDD起搏患者术后侧壁、后间隔、前壁以及下壁多个节段应变和位移显著低于术前,基底段与中间段术后平均应变和位移显著低于术前(P均<0.01);整个左心室术后应变和位移亦较术前明显降低(P均<0.05)。术前、术后左心室各节段位移从基底段、中间段到心尖段呈依次递减,而应变无这种递减规律。结论 (1)DDD起搏前后左心室心肌运动应变和位移明显不同,术后较术前明显降低;(2)VVI技术能准确地定量评价DDD起搏前后左心室心肌运动应变和位移。

Objective To assess longitudinal segmental myocardial strain and displacement of left ventricle （LV） in patients with dual chamber pacing （DDD） using velocity vector imaging （VVI） and to explore the clinical application value of VVI in assessing left ventricular motion. Methods A total of 23 patients before and after DDD pacemaker implantation were enrolled in this study. The peak systolic strain and displacement of ventricular segments were measured with VVI and compared before and after pacemaker implantation. Results Compared to the values at the baseline,the strain and displacement of lateral,interventricular septum,anterior and posterior wall of LV in patients with pacing were significantly decreased. The strain,displacement of basal and mid segments with pacing were decreased as well（Pleft ventricular strain and displacement in patients with pacing were significantly decreased than those of patients at the baseline（P0.05）. Left ventricular longitudinal displacement before and after DDD pacing was significantly decreased from basal,mid to apical segments. But no significant difference was found in longitudinal strain from basal,mid to apical segments of LV. Conclusions （1） Left ventricular strain and displacement in patients with pacing were different between those before and after DDD pacing. （2） VVI can accurately assess left ventricular strain and displacement in patients with DDD pacing,and can become a powerful mean to assess the regional myocardial function.