title: Atrial chamber remodelling in healthy pre-adolescent athletes engaged in endurance sports: A study with a longitudinal design. The CHILD study.
abstract: OBJECTIVE
  Previous studies investigated the exercise-induced adaptation of left (LA) and right atrium (RA) in adults, but little is known about respective changes in the growing heart of children. We aimed to longitudinally investigate the effects of endurance training on biatrial remodelling in preadolescent athletes.
  
  
  RESULTS
  Ninety-four children (57 endurance athletes, 37 sedentary controls; mean age 10.8±0.2 and 10.2±0.2years, respectively) were evaluated at baseline and after 5months by ECG and by two-dimensional, three-dimensional (3D) and speckle-tracking echocardiography. Athletes were trained at least 10h/week. The resting heart rate was lower in athletes (p=0.046) and decreased further after training (p<0.0001). Neither athletes nor controls had ECG evidence for LA or RA enlargement. At baseline, indexed LA volumes did not differ between groups (p=0.14) but indexed RA dimensions were larger in athletes (p=0.007). After 5months, indexed LA volumes increased in athletes but not in controls (p<0.0001, p=0.29; respectively) while indexed RA volumes increased in both groups (p<0.0001, p=0.018; respectively). At the same time, slight differences in biatrial reservoir and contractile function were found either in athletes, as demonstrated by speckle-tracking echocardiography, but 3D-derived LA and RA ejection fraction remained stable in both groups.
  
  
  CONCLUSIONS
  Endurance training influences the growing heart of preadolescent athletes with an additive increase in biatrial size, suggesting that morphological adaptations can occur also in the early phases of the sports career. Training-induced remodelling was associated with a preserved biatrial function, supporting the hypothesis of a physiological remodelling.
authors.affiliation: Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy. Electronic address: flavio.dascenzi@unisi.it.
authors.forename: Flavio
authors.initials: F
authors.lastname: D'Ascenzi
authors.affiliation: Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Solari
authors.affiliation: Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Anselmi
authors.affiliation: Division of Cardiology, Department of Cardiac, Thoracic and Vascular Sciences, Santa Maria alle Scotte Hospital, Siena, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Maffei
authors.affiliation: Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Focardi
authors.affiliation: Department of Medicine, Surgery, and NeuroScience, University of Siena, Siena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Bonifazi
authors.affiliation: Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Siena, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Mondillo
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University, and Heart Centre, Umeå, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Henein
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D056352:Athletes; D064752:Atrial Remodeling / Q000502:physiology*; D002648:Child; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology*; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D013550:Swimming / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*; D016278:Ventricular Function, Right / Q000502:physiology*
keywords: 3-dimensional echocardiography; Atrial strain; Echocardiography; Speckle-tracking echocardiography; Training; athlete's heart