斑点追踪显像技术评价正常婴幼儿、儿童及青少年收缩期左心室各节段室壁旋转运动

目的 应用超声二维斑点追踪显像技术探讨正常婴幼儿、儿童及青少年左心室各节段室壁扭转运动特征.方法 将117名3天～15岁健康受试者按年龄分为5组:婴幼儿组(3天～2岁),学龄前期组(3～5岁),学龄期组(6～9岁),青春前期组(10～12岁),青春期组(13～15岁).取胸骨旁左心室心尖和心底短轴切面对左心室扭转进行测量,分析各节段室壁旋转角度及心尖水平、心底水平的旋转角度,计算左心室整体扭转角度(Ptw),比较各组参数的差异. 结果①正常婴幼儿、儿童及青少年左心室扭转运动主要表现为心底部顺时针旋转和心尖部逆时针旋转.②在同一年龄组,心底水平各节段室壁旋转角度从前壁逐渐递增(前壁<前间隔<侧壁<后间隔<后壁<下壁)(P<0.05), 不同年龄组心底水平各节段间室壁旋转角度差异无统计学意义.③心尖水平各节段室壁旋转角度随年龄增加而变化,在青春期达到最高(P<0.05),而相同年龄组心尖水平各节段旋转角度差异无统计学意义.④同一节段室壁心尖水平与心底水平旋转角度随着年龄增长,逐渐以心尖水平的旋转为主,到青春期心尖水平与相应节段的心底水平室壁相比差异有统计学意义(P<0.01).⑤心底水平左心室旋转角度随年龄增加而变化,但差异无统计学意义,心尖水平左心室旋转角度随年龄增加而增加(P<0.05);左心室整体扭转则随年龄增加而增加,在青春前期及青春期达到最大(P<0.05).⑥不同性别儿童的旋转及扭转各参数的差异无统计学意义. 结论 在出生后至青春期随着心脏的发育,左心室心肌各节段室壁心尖水平旋转和整体扭转随年龄增加而增强.

Evaluation of left ventricular torsion in systolic phase in healthy infants, children and adolescents with two-dimensional ultrasound speckle tracking imaging

Objective To evaluate left ventricular torsion (LVtor) and twist of different segments in systolic phase of healthy infants, children and adolescents with two-dimensional ultrasound speckle tracking imaging (STI). Methods One hundred and seventeen healthy subjects aged from 3 days to 15 years were divided into 5 groups: infants (3 days-2 years), pre-school age children (3-5 years), school age children (6-9 years), preadolescent (10-12 years) and adolescent age (13-15 years). Basal and apical short-axis images of left ventricle were acquired to analyze torsion of every segment and LV torsion. The peak twist (Ptw) of left ventricular was calculated, and the values of different groups were compared. Results ①Seen from the apex level, the normal LV performed wringing motion with clockwise rotation at the base and counterclockwise rotation at the apex in infants, children and adolescents. ②Seen from the short-axis basal level, torsion angle was the biggest in inferior, but the smallest in anterior in same age group (P<0.05). In different age group, there was no statistical difference in torsion angle at basal level. ③Torsion angle of short axis apex level increased with age increasing, and reached peak in adolescents. No statistical difference was found in torsion angle of every segments in apical level among subjects in the same age group. ④Torsion angle of every segment in apical and basal level changed with age increased while ventricular wall rotating mainly with apical plane gradually. In adolescents, significant difference was found in torsion angle in same segments between basal and apical plane (P<0.01). ⑤Torsion of the basal plane of left ventricular changed with age increasing, but no statistical difference was found. Torsion of the apical plane of left ventricular increased with age increasing (P<0.05). Ptw of left ventricular increased with age increasing, and reached the peak in preadolescence and adolescence. ⑥No statistical difference was found in all parameters of torsion and rotation between males and females. Conclusion LVtor in every segment in apical plane and Ptw of left ventricular increase with age increasing before adolescence.