PATHOLOGICAL CARDIAC REMODELING IN ENDURANCE ATHLETES: A NARRATIVE REVIEW

Exercise-induced atrial remodeling in endurance athletes has emerged as a topic of growing interest in sports cardiology, particularly given the possibility that initially physiological adaptations may evolve into structural and functional changes with potential clinical relevance. Prolonged and high-intensity exercise imposes chronic volume overload on the atrial chambers, promoting progressive dilation, increased wall stress, and alterations in atrial mechanics. In this context, this narrative review aimed to critically analyze the available evidence on atrial remodeling in endurance athletes, with emphasis on the underlying mechanisms, determinants of adaptation, and the limits between physiology and potential pathology. The analyzed studies consistently demonstrate that endurance athletes present increased atrial volumes, especially of the left atrium, with a dose-response relationship between cumulative training load and the magnitude of dilation. From a functional perspective, the literature shows heterogeneous findings, with reduced atrial strain indices in some athlete groups, whereas other studies describe preservation of mechanical function within physiological limits. In addition, sex-related differences, training level, and duration of exposure appear to modulate the intensity of these adaptations. An association has also been observed between atrial remodeling, inflammatory biomarkers, and a higher propensity for the development of atrial fibrillation in veteran athletes, suggesting that atrial adaptation should not be interpreted in a dichotomous manner. It is concluded that atrial remodeling in endurance athletes represents an adaptive continuum whose final expression depends on the interaction among training load, individual susceptibility, and duration of exposure, requiring careful interpretation within the context of sports cardiology.