超声斑点追踪成像技术评价健康儿童左室心肌径向应变特征

Quantification of radial strain in healthy children by speckle tracking imaging

目的：探讨不同年龄组健康儿童左室局部心肌收缩期径向应变特征。方法：164例健康儿童分为婴、幼儿组24例（0～2岁,A组）、学龄前组32例（3～5岁,B组）、学龄期组33例（6～9岁,C组）、青春前期组19例（10～13岁,D组）、青春期组56例（13～18岁,E组）。获取并存储胸骨旁左室短轴二尖瓣、乳头肌及心尖水平观连续3个心动周期二维动态图像,应用GE EchoPAC工作站分析并获得左室18个节段的局部心肌收缩期径向峰值应变。结果：1健康儿童左心室局部心肌收缩期径向峰值应变（SR）：不同年龄组SR测值无统计学差异。左室前间隔基底段SR与心率有较弱关系（R^2=0.025,P=0.042）,其余节段SR与心率及年龄均无关。2健康儿童二尖瓣水平及乳头肌水平前间隔与前壁中间段差异有统计学意义（P〈0.05）,其余室壁节段间SR差异无统计学意义;除少数节段外,同一室壁不同水平节段比较SR差异有统计学意义（P〈0.05）。结论：儿童自婴幼儿至成年期左室局部心肌径向应变测值较均一,可作为评价儿童心脏收缩功能随访的有用指标。

Objective：To evaluate the characteristic of regional radial strain in healthy children at different age stages by speckle tracking imaging.Method：A total of 164 healthy children were divided into 5groups：between 0and 2years old was classified as group A,3to 5years old as group B,6to 9years old as group C,10 to 12years old as group D,and 13 to 18years old as group E.Left ventricular short axis views at the basal level,middle and apex levels were performed,and the dynamic 2-dimensional gray images in 3heart cycles were obtained.All images were analysed off-line using EchoPAC workstation and regional radial strains were acquired.Result：1The characteristic of regional radial systolic peak strain（SR）：SR showed no significant difference in 5groups.The regional SR at the basal anterior septum was found to be associated with heart rate（R2=0.025,P=0.042）,while SR at other segments were independent of age and heart rate.2At the base and middle levels,the SR were statistically significant only in the anterior septum and anterior segments（P〈0.05）.SR in the most segments had significant difference when compared at different levels（P〈0.05）.Conclusion：The parameters of SR were homogeneous in healthy children at different age stages,which can be helpful to follow up of LV contraction in children.