Some noninvasive parameters of cardiovascular dynamics in obese children were studied. Obesity was defined as a body mass index >90th percentile for age and gender. The groups of 70 normal weighted and 70 obese children age 8 - 15 years were examined. The method of echocardiography (ECHO), quantitative balistocardiography (Q-BCG) and thoracic electrical bioimpedance (TEB) were used. Bodymass index (BMI) or body surface area (BSA) were calculated. By ECHO ejection fraction (EF), E/A index and blood flow velocity in ascending aorta (VmaxAo by Doppler) were made. By Q-BCG characteristic quantities of systolic force (F) and minute cardiac force (MF), by TEB ejection fraction (EF), index of contractility (IC) and acceleration index (ACI) were measured. In echocardiographic examinations of normal weighted and obese boys it was stated that in obese boys the compliance of the left ventricle and the maximal blood flow velocity in aorta are lower. By comparing normal weighted and obese children by Q-BCG it may be summarized that in the obese there is significantly smaller systolic force per kilogram of body weight (F/kg) and minute cardiac force per kilogram ob body weight (MF/kg) in both sexes while heart rate (HR) is not different. Strong inverse relationships between BSA and EF (ECHO), BMI and EF (TEB), BMI and IC (TEB) BMI and MF/kg (Q-BCG) were found. Inverse relationships were stated also between BMI and F/kg (Q-BCG) and between BMI and ACI (TEB). In conclusion, generalizing these results there is a trend of lowering systolic force, minute cardiac force and cardiac efficiency with increasing body fat content. These results, together with known lower capillary density and increased total blood vessel length in obese, define the cardiovascular risk factor in adults.

        Key words: cardiovascular dynamics, obesity, children, quantitative balistocardiography (Q-BCG)