Normal Values for Left Ventricular Mass in Relation to Lean Body Mass in Child and Adolescent Athletes.

It has been demonstrated that regular sport activity in children leads to physiological changes in the heart including increased left ventricular (LV) myocardial thickness and mass (LVM). The aim of the study was to establish the first specific normal values of LVM for child and adolescent athletes. Parasternal long-axis, 2D-guided echocardiographic measurements were obtained from a group of 791 Caucasian child athletes (age 5-18 years, 58.7% boys). For the preparation of normative data, LVM-for-lean body mass (LBM) reference curves were constructed using the LMS method. Then, a simple correlation plot was constructed to analyse the concordant and discordant indications of left ventricular hypertrophy (LVH), defined as LVM-for-LBM above the 95th percentile, according to the newly created and previously published normative data on LVM-for-LBM in the general population of children. Reference scatter plots of LVM-for-LBM for boys and girls in the analysed group of children practicing sports were presented, showing mean values of LVM and z-scores. The application to the studied group of reference centiles established for the general population of children would lead to false positive misclassification of increased LVH in 5.8% of the girls and 17.0% of the boys. We present the first specific normative data for LV mass in relation to lean body mass in Caucasian children and adolescents engaged in regular sport activities. The application of specific normative data for LV mass results in fewer false positive findings of left ventricular hypertrophy in this group than that of reference values for general paediatric population.