定量组织速度成像技术探讨小儿肺动脉瓣环运动参数与肺动脉高压的关系

目的:探讨定量组织速度成像( QTVI)技术测量小儿肺动脉瓣环运动参数与肺动脉高压的关系.方法:应用QTVI技术在剑下右室流出道长轴切面或胸骨旁大动脉短轴切面,取样容积置于肺动脉瓣环处获取肺动脉瓣环运动速度和时间参数.比较32例先天性心脏病合并肺动脉高压患儿与正常小儿肺动脉瓣环运动参数的变化.结果:32例正常小儿肺动脉瓣环处获取肺动脉瓣环运动速度-时间曲线的形态与三尖瓣环运动速度-时间曲线相类似,32例肺动脉高压患儿QTVI肺动脉瓣环速度参数Ea/Aa 0.68±0.36,明显低于正常小儿Ea/Aa 1.18±0.43,P＜0.001.32例肺动脉高压患儿QTVI按肺动脉瓣环时间参数计算的Tei指数0.82±0.34,明显高于正常小儿Tei指数0.37±0.05,P＜0.001.肺动脉高压患儿QTVI按肺动脉瓣环时间参数计算的Tei指数与肺血管阻力呈正相关,r=0.556(P＜0.001).结论:QTVI测量的肺动脉瓣环运动形态与三尖瓣环运动形态相类似;肺动脉高压时肺动脉瓣环速度Ea/Aa比值降低,Tei指数增高,Tei指数与肺血管阻力呈正相关.

Characteristics of pulmonary valve annular motion identified by quantitative tissue velocity imaging in children with pulmonary hypertension

Objective: To investigate the characteristics of pulmonary valve annular motion by quantitative tissue velocity imaging(QTVI) in children with pulmonary hypertension. Methods: The pulmonary valve annular motion was assessed by QTVI in 32 children with pulmonary hypertension and 32 healthy children.The QTVI sample volume was set at the point of pulmonary valve annulus to acquire speed-time curve and the parameters from the views of parasternal aortic short-axis or subxiphoid right ventricular outflow long-axis.The parameters of pulmonary valve annular motion of children with pulmonary hypertension were compared to those of normal children. Results: The speed-time curve of pulmonary valve annulus was similar with that of tricuspid annulus in normal children.Compared to normal children,the ratio of Ea/Aa(the velocity parameter of pulmonary valve annular motion) was significantly lower in children with pulmonary hypertension(0.68±0.36 vs 1.18±0.43,P <0.001);and the value of QTVI-Tei index at the pulmonary annulus was significantly higher(0.82±0.34 vs 0.37±0.05,P <0.001).The QTVI-Tei index was positively correlated with the resistance of pulmonary vessel(r =0.556,P <0.001). Conclusions: The ratio of Ea/Aa is decreased,the value of QTVI-Tei index is increased and QTVI-Tei index is positively correlated with the resistance of pulmonary vessel in children with pulmonary hypertension.