速度向量成像技术检测胎儿心肌节段功能的临床研究

Evaluation of regional left ventricular longitudinal function in 151 normal fetuses using velocity vector imaging

目的探讨速度向量成像技术检测正常胎儿左室心肌节段功能的临床应用价值。方法应用Sequoia512彩色多普勒超声诊断系统，在四腔心观采集151例孕18～40周的正常胎儿超声图像，用心肌速度向量软件分析左室后间隔和侧壁心肌长轴方向收缩期和舒张期峰值速度、应变及应变率。结果各组基底段至心尖段心肌速度逐渐减低（P＜0．01），各节段心肌应变和应变率差异无统计学意义（P〉0．05）。收缩期和舒张期峰值速度随孕周的增加而增大（P＜0．01），而应变、应变率随孕周增加差异无统计学意义（P〉0．05）。结论速度向量成像技术不受声束角度、胎方位、胎心率的影响，能够无创客观地定量评价胎儿左室长轴心肌节段舒缩功能，为临床检测胎儿心脏节段功能提供了又一有效方法。

Objective To investigate the clinical value of VVI assessment normal fetal segmental myocardial performance and to establish a nomogram of normal fetus. Methods Digital dynamic fourchamber imaging of 151 healthy fetus （divided 5 groups according to gestation） were collected, then the longitudinal velocity,strain and strain rate of interventricular septal and left lateral wall were measured in systolic and diastolic period respectively. Results Normal systolic and diastolic values for tissue velocity, strain,and strain rate were established. Tissue velocity was age dependent, whereas strain and strain rate were stable throughout gestation （P 〈 0. 05）. Tissue velocity was gradually decreased from the base segment to the apical segment（ P 〈0. 01） ,whereas strain and strain rate were stable among all segments in every group（ P 〈0. 05）. Conclusions Fetal myocardial velocity,strain,and strain rate measurements are easy to obtain and reproducible, VVI is a novel noninvasive tool to assess quantitatively and objectively regional systolic and diastolic function in fetal heart, it is providing another useful modality for evaluating cardiac function.