Background: Athlete's heart (AH) is a term used to describe exercise-induced cadiac remodelling in athletes. Recent studies suggest that these changes may occur even in preadolescence, but little is known of the initial morphological changes.
Purpose: This study aims to further describe the early morphological and functional changes in the hearts of endurance athletes by examining the hearts of preadolescent athletes using traditional and three-dimensional (3D) echocardiography.
Methods: Seventy-six cross-country skiers aged 12.1±0.2 years were compared to a control group of 25 non-competing individuals aged 12.1±0.3 years. Echocardiography was performed in all subjects, including 3D acquisitions of the left ventricle (LV). Relative wall thickness (RWT) was calculated by multiplying the LV posterior wall by two and dividing it by the LV internal diameter.
Results: The cross-country skiers had a significantly greater indexed VO2 max, septal thickness, posterior wall thickness and LV mass (Table). Athletes also had greater indexed LV diameters and higher RWT. Ejection fraction did not differ between the two groups.
Conclusion: Athletes had greater LV mass and LV chamber volumes, and also higher RWT compared to the controls. This supports the notion that there is early physiological, adaptive remodelling in preadolescent athlete's heart. Furthermore, remodelling in preadolescent athletes seems to be primarily concentric in nature.