Kutty Shelby, Deatsman Sara L, Nugent Melodee L, Russell David, Frommelt Peter C
Herma Heart Center, Children's Hospital of Wisconsin, Medical College of Wisconsin, Milwaukee, WI, USA.
Echocardiography. 2008 Mar;25(3):294-307. doi: 10.1111/j.1540-8175.2007.00584.x.
Velocity vector imaging (VVI) is a novel technique to assess regional myocardial mechanics. We evaluated the utility of VVI in the assessment of right ventricular (RV) function in normal children.
RV images (apical 4-chamber view, high frame rate capture) from 30 normal children (mean 8.7 years; range 1.1-18) were selected. Longitudinal myocardial velocities, peak systolic strain (PSS), maximal longitudinal displacement (LD), and times to peak for these parameters were obtained from six RV segments. Simultaneous Doppler tissue imaging (DTI) derived peak systolic and early diastolic velocities were obtained from the free tricuspid annulus. Measurements were made independently by two observers.
Qualitative analysis shows dominant longitudinal systolic and diastolic myocardial motion, particularly at the basal segments. Velocities and LD were greatest at the basal segments and decreased from base to apex. PSS values were less consistent between segments and observers, with the greatest PSS generally found in the apical segments. LD and time to peak displacement (TPD) were the most reproducible. TPD in the basal segments were strikingly similar in each patient and correlated with R-R intervals. Peak diastolic velocities in the right base did correlate with corresponding annular DTI velocities; DTI velocities were consistently higher than VVI velocities.
RV segmental velocities and LD are reliably obtained by VVI. PSS is less reproducible. LD is a reproducible measure of systolic function and TPD appears to be useful in the assessment of synchrony. Correlation of these findings with children who have known RV pathology is an important next step.
速度向量成像（VVI）是一种评估局部心肌力学的新技术。我们评估了VVI在评估正常儿童右心室（RV）功能中的效用。
选取30名正常儿童（平均8.7岁；范围1.1 - 18岁）的RV图像（心尖四腔心切面，高帧率采集）。从六个RV节段获取纵向心肌速度、收缩期峰值应变（PSS）、最大纵向位移（LD）以及这些参数的达峰时间。同时从三尖瓣游离环获取多普勒组织成像（DTI）得出的收缩期峰值和舒张早期速度。测量由两名观察者独立进行。
定性分析显示，心肌纵向收缩期和舒张期运动占主导，尤其是在基底部节段。速度和LD在基底部节段最大，从基部到心尖逐渐降低。各节段和观察者之间PSS值的一致性较差，PSS最大值通常出现在心尖节段。LD和峰值位移时间（TPD）的可重复性最高。每位患者基底部节段的TPD非常相似，且与R - R间期相关。右心室基部的舒张期峰值速度与相应的瓣环DTI速度确实相关；DTI速度始终高于VVI速度。
通过VVI可可靠地获取RV节段速度和LD。PSS的可重复性较差。LD是收缩功能的可重复测量指标，TPD似乎有助于评估同步性。下一步重要的是将这些发现与已知RV病变的儿童进行关联。
