应用速度向量成像技术评价胎儿左室纵向整体和节段功能

Assessment of left ventricular global and regional longitudinal function in fetus using velocity vector imaging

目的应用速度向量成像技术(VVI)测量健康胎儿左室整体和节段纵向应变、应变率和峰值速度,以评价左室功能。方法应用超声心动图采集健康胎儿四腔心切面,存储动态数字图像并进行分析。从二尖瓣前叶瓣环开始沿室间隔心内膜逐点勾画扩展到心尖部,再从侧壁延伸到二尖瓣后瓣瓣环处结束。将室间隔和侧壁分为基底、中间及心尖六个节段并进行自动计算,测量左室整体和各节段室间隔及左室侧壁节段的纵向应变、应变率和峰值速度,整体功能以各节段的平均值计算。将各节段的测量结果分别与左室整体结果进行比较。结果在53例胎儿中,4 9例经V V I技术成功完成评价,检测成功率9 2.4%。左室整体心肌应变为–1 3.7 2%±3.9 9%,收缩期应变率为–2.59±0.44/s,舒张期应变率为2.43±0.38/s,与各节段的心肌应变及应变率比较差异均无统计学意义(P>0.05)。左室整体峰值速度收缩期为1.68±0.46cm/s,舒张期为1.51±0.41cm/s,而节段峰值速度从室间隔和侧壁基底部到心尖部逐渐降低。左室整体峰值速度与心尖和基底部比较差异有统计学意义(P<0.05)。结论采用VVI技术测量胎儿左室整体应变、应变率和峰值速度是可行的。左室整体测量可作为评价胎儿心脏功能的一种新的检测工具。

Objective To measure the let ventricle global and segmental longitudinal strain,strain rate,and peak velocity in normal fetuses using velocity vector imaging（VVI） for the assessment of the left ventricular function.Methods Detailed prenatal echocardiographic examinations were performed in 53 normal fetuses.Digital dynamic four-chamber views were collected and analyzed oline.In the four-chamber view,the interventricular septum and let ventricular lateral wall were divided into basal,middle and apical segments,in a total of six segments.Endocardial tracing began at the edge of the anterior mitral valve annulus,along endocardium of interventricular septum,extended to the ventricular apex,and returned to posterior mitral valve annulus along lateral ventricular wall edge.he global and segmental longitudinal strain,strain rate and peak velocity of the interventricular septum and let ventricular lateral wall were measured,the global function was calculated by an average of all segments.Segmental measurements were compared to global results.Results Fity-three fetuses were enrolled in this study,and the VVI analysis was successful in 49,the success rate was 92.4%.he global let ventricular strain was –13.72%±3.99%,and the strain rate was –2.59±0.44/s and 2.43±0.38/s in systole and diastole respectively.No diference was found between segmental and global ventricular strain and strain rate.he let global ventricular peak velocity was 1.68±0.46cm/s and 1.51±0.41cm/s in systole and diastole respectively.he peak segmental velocity in systole and diastole decreased from the base of interventricular septum and lateral wall to ventricular apex.The global left ventricular peak velocity was signiicantly diferent from the peak velocity of apical and basal segments（P0.05）.Conclusions Measurement of global let ventricular longitudinal strain,strain rate and peak velocity is feasible in fetuses by using VVI.Global let ventricular function may be a new index for assessment of quantitative fetal cardiac function.