Training-induced right ventricular remodelling in pre-adolescent endurance athletes: The athlete's heart in children

Aims: Little is known about the adaptation of the right ventricle (RV) to endurance exercise in children. The aim of this study was to assess the effects of 5 months of intensive training on RV morphology and function in preado-lescent endurance athletes. Methods: Ninety-four children were evaluated in this study. Fifty-seven male competitive swimmers (aged 10.8 +/- 0.2 years) were evaluated before (baseline) and after 5 months of the training (peak-training), and compared to 37 age-and sex-matched non-athlete children evaluated at baseline and after 5 months of natural growth. All subjects were asymptomatic, with negative family history for cardiomyopathies. Results: At baseline no differenceswere found between athletes and controls for indexed RV outflow tract (RVOT) (18.5 +/- 2.7 vs. 16.8 +/- 5.0 mm/m(2), p = 0.18) and RV basal end-diastolic diameter (EDD) (24.9 +/- 4.1 vs. 23.6 +/- 3.0 mm/m(2), p = 0.15). After 5 months, indexed RVOT and RV basal EDD significantly increased in athletes (20.2 +/- 2.9 mm/m(2) and 25.4 +/- 3.3 mm/m(2), p < 0.0001 vs. baseline) while no differences were observed in controls (p = 0.84 and p = 0.25). Despite the increase in RV size, RV function remained normal in athletes, with no changes in RV fractional area change (p = 0.97), s' value (p = 0.22), and RV longitudinal strain (p = 0.28). Conclusions: Endurance training influences the growing heart of male preadolescent athletes with an addictive increase in RV dimensions, with a preserved RV function. Therefore, in children engaged in endurance sports the increase in RV size associated with normal RV function represents a physiological expression of the athlete's heart and should not be misinterpreted as an expression of incipient RV cardiomyopathy. (C) 2017 Elsevier B.V. All rights reserved.