速度向量成像估测正常儿童心室长轴心肌节段功能的研究

Study on segmental myocardial function of ventricular longitude in normal children by velocity vector imaging

目的通过速度向量成像(VVI)探索正常儿童左右心室长轴各节段运动的变化规律。方法采集44名健康儿童心尖四腔切面,Syngo Workplace软件测定各节段的速度、应变、应变率和位移,分析VVI参数与年龄之间的关系。结果①正常儿童左右心室的速度、应变、应变率和位移从基底段到心尖段依次降低。右室游离壁的速度、位移、应变和应变率明显高于左室游离壁和室间隔的相应节段(P<0.05)。②左室游离壁基底段和中间段的速度与年龄具有较好的相关性(r=0.436,P<0.01;r=0.464,P<0.01);右室游离壁的各节段速度与年龄无相关性(P>0.05)。③左右室的游离壁基底段的应变与年龄具有较好的相关性(r=0.478,P<0.01;r=0.497,P<0.01);右室游离璧中间段的应变率与年龄有较好的相关性(r=0.520,P<0.01)。结论应变和应变率受到年龄的影响,因此在估测局部心肌节段功能时应考虑到该影响。

To explore the change characteristics of different segment movement of left and right ventricular longitude in normal children by velocity vector imaging （VVI）. Methods Longitudinal image at apical 4-chamber view were obtained in 44 healthy children. Velocity, strain, strain rate and displacement were measured and compared by Syngo Workplace software, then the relationship between VVI parameters and age was analyzed. Results The longitudinal velocity, strain, strain rate and displacement of left and right ventricle were gradually decreased from base to apex in normal children. The segmental velocity, strain, SR and displacement were higher in RV than those in LV and septum（P 〈 0.05 ）. Velocity at basal and mid LV free wall had good correlation with age（ r = 0. 436, P 〈 0.01 ; r = 0. 464, P 〈 0.01 ） , while velocity at different segments of RV free wall had no correlation with age （ P 〉 0.05 ）. Strain at basal RV and LV had good correlation with age （ r = 0. 478, P 〈 0.01 ;r = 0. 497 ,P 〈 0.01 ）, strain rate at mid of RV free wall was also well correlated with age （r = 0. 520, P 〈 0.01 ）. Conclusion Strain and strain rate could be affected by age, which should be taken into consideration in estimation of ventricular myocardial function.