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

Abstract

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.

Normal basic 2D echocardiographic values to screen and follow up the athlete's heart from juniors to adults: What is known and what is missing. A critical review

“…15,22,27 According to these criteria, only a few studies achieved a sufficient sample size in adult athletes, 14,23,24,35 while others 10–12,19,22 were close to achieving ‘the target’ (from 600 to 620 subjects). Most of the available paediatric studies 8,9,21,22,26 had an adequate sample size, which should be least 600–700 subjects. 3,4 Only a few authors 10–12,16,17 evaluated a broad dataset, while most studies were limited to some echocardiographic parameters.…”

“…3–6 However, nomograms calculated in the general population cannot be applied to athletes, a setting in which the cardiac dimensions are physiologically increased. 8–40 Great advances have been made in screening athletes' hearts based on ECG findings, 41 and basic criteria have been established, 41 while echocardiographic criteria are less well defined. Thus, in recent years, echocardiographic nomograms specific for athletes have been proposed.…”

“…In particular, a few groups in Italy 10–12,15,23–25 and in other European countries 14,17–19,21,22,31,32 have presented a series of echocardiographic nomograms in elite adult athletes. A few studies on junior athletes 8,9,20,21,22,26 have also been published. These nomograms should help to distinguish between physiology and pathology.…”

Left ventricular mass normalization in child and adolescent athletes must account for sex differences

“…The study participants were child and adolescent athletes. The athletic population may be considered special because regular exercise contributes to an increase in cardiac size [ 15 ], and specific LVM normative data are recommended for child and adolescent athletes [ 20 ]. A question may thus arise as to whether the results of the study should be applied to all children and adolescents.…”

“…In our recent studies, we analyzed a problem of the correct body size variable for cardiac LVM normalization [17] and the issue of an accurate and convenient method for cardiac size scaling [18]. In previous studies, we developed normative data for children and adolescents practicing sport and compared them to the normative data generated for the general pediatric population [19,20]. When we were working on the topic of LVM normalization for body size, a question arose: should LVM normative data, or generally normative data of the LV dimensions, be sex-specific or not?…”