Assessment Of Early Changes Of Left Ventricular Myocardial Strain In Childhood Simple Obesity With Three-dimensional Speckle Tracking Imaging

Objective:The aim of this study was to validate three-dimensional speckle tracking imaging(3D-STI)as a method to quantify the early changes of left ventricular myocardial function and to assess the usefulness of 3D-STI as an estimation in the reconstruction of myocardium,for the sake of providing reliable basement for early clinical intervention and prevention of childhood simple obesity.Methods:41 obese children(obese group)and 19 overweight children(overweight group)aged 7~15 years old were contrasted with 56 age and sex-matched healthy subjects(control group).Three groups children were all studied with conventional transthoracic echocardiography and 3D speckle tracking echocardiography.Conventional echocardiography was performed for the measurement of the following indices: Interventricular septal end-diastolic dimension(IVSd),left ventricular posterior wall end-diastolic dimension(LVPWd),End-diastolic volume(LVEDV),end-systolic volume(LVESV)and ejection fraction of left ventricular(LVEF).The real-time 3D full volume datasets were recorded to measure left ventricular global longitudinal peak systolic strain(GLS),longitudinal peak systolic strain of 16 segments,left ventricular global radial peak systolic strain(GRS),radial peak systolic strain of 16 segments,left ventricular global circumferential peak systolic strain(GCS),circumferential peak systolic strain of 16 segments,global twist angle(GTA),left ventricular mass(LVM)and were analyzed by 3DSTI analysis software in Tom-tec workstation.The correlations among LVEF,BMI,LVM,GLS,GRS,GCS were analyzed respectively.Results:(1)Compared with control group,obese group had significantly greater LVSd?LVPWd?LVEDV and LVESV(p<0.05).Compared with control group,overweight group had significantly greater LVSd?LVEDV and LVESV(p<0.05).(2)Compared with control group,GLS?GRS?GCS?GTA?LVM of obese group were all significantly lower(p<0.05).Compared with overweight group,GCS?GTA of obese group were all significantly lower(p<0.05).Compared with control group,GLS?GRS?LVM of overweight group were all significantly lower(p<0.05).(3)Compared with control group,the longitutional strain of anterior septal wall,anterior wall,posterior septal wall at based level and all the segments at middle level and anterior wall,lateral wall,septal wall at apical level of obese group were all significantly lower(p<0.05).Compared with overweight group,the longitutional strain of anterior wall,septal wall at apical level of obese group were all significantly lower(p < 0.05).Compared with control group,the longitutional strain of anterior wall,posterior septal wall at based level and anterior septal wall,anterior wall,posterior wall,later wall,septal wall at middle level of overweight group were all significantly lower(p<0.05).(4)Compared with control group,the radial strain of anterior septal wall,anterior wall,posterior wall,lateral wall,posterior septal wall at based level and all the segments at middle level and anterior wall,lateral wall,septal wall at apical level of obese group were all significantly lower(p< 0.05).Compared with overweight group,the radial strain of all the segments at apical level of obese group were all significantly lower(p < 0.05).Compared with control group,the radial strain of anterior septal wall,lateral wall,posterior wall,posterior septal wall at based level and anterior septal wall,anterior wall,lateral wall,posterior septal wall at middlel level of overweight group were all significantly lower(p<0.05).(5)Compared with control group,the circumferential strain of anterior septal wall,anterior wall,posterior wall,lateral wall,posterior septal wall at based level and middle level and anterior wall,lateral wall at apical level of obese group were all significantly lower(p<0.05).Compared with overweight group,the circumferential strain of lateral wall at based level and posterior wall,lateral wall at middle level and anterior wall,lateral wall,septal wall at apical level of obese group was significantly lower(p<0.05).Compared with control group,the circumferential strain of anterior septal wall,lateral wall,posterior septal wall at based level of overweight group were all significantly lower(p<0.05).(6)GLS was significantly correlated with BMI and LVM(r=0.516,P<0.05;r=0.316,P<0.05),but show no correlation with LVEF(P>0.05).GRS was significantly correlated with BMI and LVM(r=0.499,P<0.05;r=0.348,P<0.05),but show no correlation with LVEF(P > 0.05).GCS was significantly correlated with BMI and LVM(r=0.416,P<0.05;r=0.329,P<0.05),but show no correlation with LVEF(P>0.05).Conclusion:(1)Overweight youth already present signs of impaired left ventricular subclinical myocardial function and myocardial systolic function become worse as BMI or LVM become higher.(2)left ventricle begin to remodle as the increase of BMI which would lead to myocardial systolic decreasing disproportionately.(3)3D-STI can quantify cardiac systolic function comprehensively and is more sensitive in detecting the alteration of myocardial function comparing to conventional echocardiography.