The Evaluation of Left Ventriclular Function Determined by Conventional Echocardiography and Tissue Doppler Imaging in Obese Children less than 10-year-old

ABSTRACT

PURPOSE: The objective of the study was to determine the anatomical and functional changes of the left ventricle (LV) in obese children less than 10 years old using the conventional echocardiography and tissue doppler. METHODS: A total of 45 children were enrolled for the study of which all including 12 obese children whose body mass index (BMI) exceeded 95th percentile for age and sex adjusted standard BMI of Korean children were screened by conventional echocardiographic and tissue doppler imaging examinations at Kangneung Asan hospital during June 2005 to October 2005. RESULTS: There was no statistical difference in age between control and obese group (CG vs. OG 7.1+/-1.2 yr. vs. 8.0+/-1.5 yr). The average BMI in OG was 22.6+/-2.4 kg/m2. The conventional echocardiographic indices of LV including the diastolic LVID (LV Internal Dimension), LVPWT (LV Posterior Wall Thickness), the systolic IVST (Interventricular Septal Thickness), LVID and LVPWT were higher in OG compared to CG. Also, the LV mass (LVm), LV mass index (LVmI), fractional shortening (FS) and ejection fraction (EF) were higher in OG than CG. however, the early and late diastolic mitral inflow velocities (E, A) and their ratios (E/A) showed no differences between the two groups. The myocardial performance index (MPI) was higher in OG than CG 0.42+/-0.09 vs. 0.35+/-0.07. The isovolemic relaxation time (IVRT) was prolonged in OG compared to CG 55+/-8 ms vs. 46+/-9 ms. The indices of TDI including the systolic peak velocity (s') and late diastolic peak velocity (a') at mid-IVS were higher in OG than CG, but the early diastolic peak velocity (e'), e'/a', E/e' at mid-IVS showed no differences between the two groups. The indices of TDI at the lateral portion of mital annulus showed no differences between the two groups. CONCLUSION: This study showed that increased LVm, LVmI, EF, FS, MPI, IVRT and a' in obese children less than 10 years old. This result showed anatomical and functional early change of LV due to obesity similar to adult and adolescence more than 10 years old.