Evaluation of left ventricular torsion in systolic phase in healthy infants, children and adolescents with two-dimensional ultrasound speckle tracking imaging / 中国医学影像技术

ABSTRACT

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.