速度向量成像评价DDD起搏前后心室收缩功能

目的 应用速度向量成像(velocity vector imaging,VVI)技术分析DDD起搏前后心室心肌运动速度、应变、应变率变化规律,初步探讨VVI技术的应用价值.方法 对17例DDD起搏患者于术前术后采用VVI技术检测心室各节段心肌收缩期纵向运动速度、应变、应变率和径向运动速度、环向应变及应变率,并比较术前术后差异.结果 术前术后左、右心室各室壁基底段、中间段、心尖段收缩期纵向峰值运动速度依次递减,基底段的速度最大,心尖段的速度最小;收缩期纵向应变、应变率在基底段、中间段及心尖段差异无统计学意义.左心室各室壁收缩期径向峰值运动速度、环向应变及应变率差异无统计学意义.右室后间隔与游离壁术前、术后平均峰值运动速度与应变率和术后平均应变均高于左室后间隔与侧壁,术后右室平均应变及应变率均高于左室.与术前相比,术后左室平均应变显著降低.结论 VVI技术能准确地定量评价DDD术前后节段性室壁功能及其变化.

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

Objective To appraise the clinical value of velocity vector imaging(VVI) by analyzing the peak systolic velocities,strain and strain rate of ventricular segments in patients with DDD pacing. Methods eventeen patients with DDD pacing were enrolled in this study. The peak systolic velocities, strain andstrain rate of ventricular segments were measured with VVI. The difference at baseline and after pacemaker implantation was analyzed. Results Left and right ventricular (LV and RV) longitudinal peak velocities at baseline and after DDD pacing were significantly decreasing from basal, mid to apical segments. But no significant difference was found in longitudinal strain,strain rate and radial motion characteristic of LV. The mean systolic velocities and strain rate at baseline and after pacemaker implantation and strain with pacing of RV posterior septum and free wall were higher than those of posterior septum and lateral segment of LV respectively. The mean strain and strain rate of RV after pacing were higher than that of LV. Compared with the values at baseline, mean strain of LV with pacing was lower significantly. Conclusions VVI can accurately assess ventricular systolic function in patients with DDD pacing, and can become a powerful means in assessing the regional myocardial function.