title: Electrocardiographic Changes Induced by Endurance Training and Pubertal Development in Male Children.
abstract: Training-induced electrocardiographic changes are common in adult athletes. However, a few data are available on electrocardiogram (ECG) in preadolescent athletes and little is known about the potential changes induced by training on 12-lead electrocardiogram (ECG) at rest. Twelve-lead ECGs at rest and complete echocardiographic examinations were performed in 94 children (57 endurance athletes, 37 sedentary controls; mean age 10.8 ± 0.2 and 10.2 ± 0.2 years, respectively) at baseline and after 5 months of growth and training in athletes and of natural growth in controls. At baseline, athletes had lower heart rate at rest compared with controls (p = 0.046) and a further decrease was observed after training (p <0.0001). An incomplete right bundle branch block was found in 19% of athletes and 15% of controls (p = 0.69) with no changes after training. Although none of the athletes showed negative T waves from V1 to V3, 6% of controls at baseline had T-wave inversion V1 to V3 with a decrease to 3% after 5 months (p = 0.16). The early repolarization pattern did not differ between athletes and controls and was correlated with Tanner's scale score in the overall population both at first and second evaluation (R = 0.30, R = 0.27, p = 0.005, p = 0.012, respectively). No correlations were found between ECG and echocardiographic data. In conclusion, 12-lead ECG at rest is not substantially affected by training in children, despite a physiological increase in cavity size. Thus, in preadolescent athletes, 12-lead ECG at rest does not reflect exercise-induced morphologic remodeling and seems to be influenced more by sexual maturation than by training.
authors.affiliation: Division of Cardiology, Department of Medical Biotechnologies, University of Siena, Siena, Italy. Electronic address: flavio.dascenzi@unisi.it.
authors.forename: Flavio
authors.initials: F
authors.lastname: D'Ascenzi
authors.affiliation: Division of Cardiology, Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Solari
authors.affiliation: Division of Cardiology, Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Anselmi
authors.affiliation: Division of Cardiology, Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Valentini
authors.affiliation: Division of Cardiology, Department of Cardiac, Thoracic, and Vascular Sciences, Santa Maria alle Scotte Hospital, Siena, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Barbati
authors.affiliation: Department of Social, Political and Cognitive Sciences, University of Siena, Siena, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Palmitesta
authors.affiliation: Division of Cardiology, Department of Medical Biotechnologies, 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: Division of Cardiology, Department of Medical Biotechnologies, University of Siena, Siena, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Mondillo
mesh_terms: D000222:Adaptation, Physiological; D056352:Athletes; D053840:Brugada Syndrome / Q000175:diagnosis / Q000503:physiopathology*; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000503:physiopathology*; D000075224:Cardiac Conduction System Disease; D016022:Case-Control Studies; D002648:Child; D004452:Echocardiography; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D011627:Puberty; D013550:Swimming / Q000502:physiology