Quantitative Assessment Of Left Ventricular Function In Simple Obese Children By Strain Rate Imaging

Objective: To investigate the effects of obesity on systolic function of regional myocardial and the global cardiac function of healthy children with excess weight using echocardiography and strain rate imaging .Methods: we studied 60 simple obese children (Group1) and 60 healthy lean children (Group2) comparable for age and sex by echocardiography .Children in Group 1 are all healthy without other disease such as hypertension and diabetes mellitus .We got basic clinical data such as age , gender, body weight, body height, blood pressure and heart rate. Then we got following parameters by conventional two-dimensional and Doppler echocardiography : left atrium diameter ,left ventricle end diastolic diameter, inter ventricular septal(IVS)thickness, left ventricular post wall(LVPW)thickness, ejection fate. Left ventricular mass were calculated by formula of Devereux. Tissue Doppler images were obtained in the standard echocardiographic views of the LV apical four-chamber (A4C) and two-chamber (A2C) views for three cardiac cycles. All data were acquired at a frame rate of 120±15 frames/s. Tissue Doppler myocardial imaging data were stored in digital format and analyzed offline using QLAB5.0 software . Then we got the peak systolic strain rate (SRs), peak systolic strain (e) and peak systolic velocity (Vs) on the IVS and lateral, anterior and inferior wall of left ventricle. All data were average of three cardiac cycles. All the analyses were performed using SSPS 11.5 and quantitative data were compared using t test .The correlations of different data were studied by linear regression analyses.Results: Standard echocardiographic indices of global systolic function such as global cardiac function (LVEF) were similar in the two groups (p>0.05). Heart rate and blood pressure were comparable between groups (p>0.05). LA LV diameters and IVS LVPW thickness were increased in obese children when compared with referents (p<0.05). Obese children showed regional longitudinal peak systolic strain rate and strain lower (p<0.05) than those of referents in left ventricle. In multivariable analysis, average LV peak systolic strain was significantly correlated with body mass index (p=0.003 r=0.12).Conclusions: Strain rate imaging is a new quantitative method to assess regional cardiac myocardial function and it is more sensitive and effective than other methods.Obesity is associated with significant reduction in systolic myocardial function and cardiac constitution in childhood in left ventricle . There for, it is very important to prevent the development of obesity in children as early as possible.