Obesity-related cardiovascular behavior in children.

OBJECTIVE: Obesity is a chronic metabolic disorder and may associate with cardiovascular geometrical, structural and functional changes. The aim of this study is to assess the relationship between body mass index (BMI), body surface area (BSA) and arterial-ventricular elasticity (Ea and Ees respectively) and cardiovascular coupling and myocardial wall stress and fiber stress in obese children. PATIENTS AND METHODS: Sixty non-obese healthy children with BMI <85th percentile aged 6-17 years and 65 age and sex-matched children with BMI of ≥95th percentile, were included in the study. Beside cardiac systolic and diastolic functions, left verntricular (LV) systolic and diastolic dimensions and volumes (LVDs, LVDd, LVVs, LVVd respectively), LV mass (LVM), LV end-systolic pressure (LVESP), meridional end-systolic wall stress (ESWm), myocardial fiber stress (MFS), Midwall Shortening Fraction (SFmid), heart rate corrected circumferential fiber shortening (VCFc), predicted mid wall fiber shortening for a measured fiber stress (mid wall VCFc), right ventricular (RV) and LV work index (RVWI, LVWI), LV relative wall thickness (LVRWT), arterial elastance (Ea), LV end-systolic elastance (Ees) and end-systolic pressure volume relationship (ESPVR) were calculated. RESULTS: LVDs and LVDd, LV mass (LVM), ESWSm, MFS, SF mid, Midwall VCFc and LVWI found to be significantly (p<0.001) higher, while Ea, Ees, ejection fraction (EF), fractional shortening (FS), VCFc-ESWS, RVWI, ESWSm/LVVs, LV end-systolic pressure (Pes)/LVVs and LVM/LVVd values were significantly (p<0.001) lower among obese group. By increasing age and BMI the Ea and Ees, ESWSm/LVVS and RVWI decrease; while LVDd, LVVd and stroke volume (SV) values increase. There was a reverse-relation between BMI percentiles and EF and FS.

Arterial and left ventricular end-systolic elastance in normal children.

OBJECTIVE: Assessing the left ventricular (LV) functions in Pediatric Intensive Care Unit, and those pediatric patients with compromised ventricular performance or enhanced systolic or diastolic load e.g. congestive heart failure, hypertension, dilated/hypertrophic cardiomyopathies is a real challenge. Currently used noninvasive methods fail giving quantitative measures to asses cardiac performance and do not allow evaluation of ventriculo-arterial interaction. Non-invasive method of cardiovascular performance determination by measuring left ventricle end-systolic elastance (Ees), arterial elastance (Ea) and the ventriculoarterial coupling (VAC), though interaction between LV and arterial network, is possible. PATIENTS AND METHODS: Hundred and forty two otherwise normal children (1 week to 17 years old) were randomly selected. Routine transthoracic echocardiographic and Doppler studies were carried out by an experienced pediatric cardiologist. The results have been evaluated statistically. RESULTS: We found that the Ea and Ees(sb) show powerful negative correlation with BSA (r = -0.65, -0.72 respectively) of the children. CONCLUSIONS: We suggest that this simple measurement method may be applied at bedside to evaluate ventricular performance of the children.