Normal reference values for left ventricular peak systolic longitudinal strain and strain rate in healthy children at different ages: a preliminary analysis / 第三军医大学学报

ABSTRACT

Objective To analyze the normal reference values of left ventricular longitudinal peak systolic strain (LS) and strain rate (LSr) by two-dimensional speckle tracking imaging (2D-STI) in healthy children at different ages.Methods Clinical ultrasound data of 330 healthy children who taking physical examination in our hospital from September 2015 to November 2016 were collected and retrospectively.They were divided into 7 groups according to their ages,that is,neonate group (0 to 28 days old),infant group (28 days to 1 year old),toddle group (1 to 3 years old),pre-school group (3 to 6 years old),school age group (6 to 9 years old),pre-adolescence group (9 to 13 years old) and adolescence group (13 to 18 years old).2D-STI was performed in the 3 apical projections of left ventricle (LV).The regional peak systolic longitudinal strain and strain rate of LV were measured.Results ① Significant differences were found in the LS and LSr values from 6 segments of the same wall (P ＜ 0.05),and the LS and LSr values were gradually increased from basal segment to apical segment.②There were no significant differences in the LS,LSr and global LS (GLS) values of 18 segments between sexes (P ＞ 0.05).③ Except the basal segments of posterior wall,inferior wall and posterior septum,LS value was gradually elevated with the increase of age (LS ＜LSinfant ＜ LStoddler,pre-shool and school age ＜ LSpre-adolescence and adolescence),So was GLS value.④LS in 18 segments had a positive correlation with age,and the value of apical segment in lateral wall was most remarkably correlated (r =0.551,P ＜0.01);Regional LS had a negative correlation with heart rate,and that of middle segment in lateral wall was the most apparent (r =-0.625,P ＜ 0.01);GLS was positively influenced by age (r =0.665,P ＜ 0.01) and negatively affected by heart rate (r =-0.625,P ＜ 0.01).⑤The heterogeneities were found in the correlations of regional LSr with age and heart rate in segments and in the LSr among different age groups.Conclusion Normal reference values of LV peak LS and LSr are established for healthy children at different ages,and they possess their own characteristics.