正常儿童左心室斑点追踪成像纵向应变研究

目的 探讨我国正常儿童(0～18岁)左心室壁纵向应变特征及其与年龄的关系.方法 将130例正常儿童按年龄分为五组:幼儿组(A组,0～3岁),学龄前组(B组,3～5岁),学龄期组(C组,6～9岁),青春前期组(D组,10～12岁),青春期组(E组,13～18岁).获取左室心尖长轴连续三个心动周期图像,应用GE EchoPAC软件分析,得到左室各节段收缩期纵向峰值应变(SL)测值.结果 ①各组内比较:心尖段SL测值大于中间段及基底段,其中A组心尖段与基底段间差异均有统计学意义(P<0.05),D组后壁、侧壁、下壁、室间隔心尖段与基底段差异有统计学意义(P<0.05),E组后间隔心尖段与基底段差异有统计学意义(P<0.05).②各组间比较:五组SL测值随年龄增长大致呈递减趋势,五组SL测值除前间隔中间段、侧壁心尖段及后间隔心尖段以外,余节段差异均有统计学意义(P<0.05).A组除前壁、B组除后壁心尖段、前间隔心尖段以外,余室壁对应节段SI,测值大于D组及E组.差异有统计学意义(P<0.05).③心尖二腔观观察者内变异系数为2.0%.观察者间变异系数为2.5%;心尖三腔观观察者内及观察者间变异系数分别为1.9%、2.3%;心尖四腔观观察者内及观察者间变异系数分别为2.1%、2.8%.结论 不同年龄组正常儿童左室各对应节段长轴收缩期纵向应变分布不一,随年龄增长具有一定的规律.

Evaluation of left ventricular systolic longitudinal strain in healthy children by two dimensional speckle tracking imaging

Objective To assess the characteristic of left ventricular systolic longitudinal strain(SL) in healthy children and its relationship with age by speckle tracking imaging(STI). Methods One hundred and thirty healthy children were divided into 5 groups: classing 0 to 3 years old children together as group A,and 3 to 5 years old as group B,6 to 9 years old as group C,10 to 12 years old as group D,13 to 18 years old as group E. SL of left ventricular wall during the systole was measured. Results ①The apical SL of left ventricular wall during the systole was larger than the middle one and the basal one. Significant differences were found between apical and basal segments in group A. The apical segments of posterior wall, inferior wall ,lateral wall and ventricular septum presented significant differences with the basal one in group D. Significant difference was found between apical segments of the posterior ventricular septum and the basal one in group E. ②These parameters of the five groups trend to decrease as well as the growth of age . Compared with group D and E,SL of left ventricular wall during the systole were significantly increased in group A except anterior wall,and SL of left ventricular wall during the systole were significantly increased in group B except apical segments of the posterior wall and apical segments of the anterior ventricular septum. ③The intra-observer and inter-observer variabilities were 2.0% and 2.5% for SL measured by STI in two chamber view,1.9% and 2.3% SL in three chamber view, and 2.1% and 2. 8% in four chamber view. Conclusions The parameters of strain were not similar in left ventricular different walls and segments,and there is some relationship between SL and increasing-age.