Background—: Exercise is able to induce atrial remodeling in top-level athletes. However, evidence is mainly limited to men and based on cross-sectional studies. The aim of this prospective, longitudinal study was to investigate whether exercise is able to influence left and right atrial morphology and function also in female athletes. Methods and Results—: Two-dimensional echocardiography was performed before season and after 16 weeks of intensive training in 24 top-level female athletes. Left and right atrial myocardial deformation was assessed by two-dimensional speckle-tracking echocardiography. Left atrial volume index (24.0±3.6 versus 26.7±6.9 mL/m ² ; P <0.001) and right atrial volume index (15.66±3.09 versus 20.47±4.82 mL/m ² ; P <0.001) significantly increased after training in female athletes. Left atrial global peak atrial longitudinal strain and peak atrial contraction strain significantly decreased after training in female athletes (43.9±9.5% versus 39.8±6.5%; P <0.05 and 15.5±4.0% versus 13.9±4.0%; P <0.05, respectively). Right atrial peak atrial longitudinal strain and peak atrial contraction strain showed a similar, although non-significant decrease (42.8±10.6% versus 39.3±8.3%; 15.6±5.6% versus 13.1±6.1%, respectively). Neither biventricular E / e ′ ratio nor biatrial stiffness changed after training, suggesting that biatrial remodeling occurs in a model of volume rather than pressure overload. Conclusions—: Exercise is able to induce biatrial morphological and functional changes in female athletes. Biatrial enlargement, with normal filling pressures and low atrial stiffness, is a typical feature of the heart of female athletes. These findings should be interpreted as physiological adaptations to exercise and should be considered in the differential diagnosis with cardiomyopathies.

Conflicting evidence exists concerning right ventricular (RV) morphological and functional remodelling in trained athletes, with a very few longitudinal data prospectively investigating the RV changes. The aim of this study was to assess the morphological and functional RV changes occurring during the competitive season in young athletes engaged in the most popular team sports. Twenty-nine top-level athletes (age: 20.9 ± 6.7 years), practicing basketball and volleyball, were evaluated at pre-season, mid-season, and end-season time-points, using tissue Doppler imaging and 2D speckle-tracking echocardiography. RV basal and mid-cavity end-diastolic diameters (EDDs; overall P = 0.011 and P < 0.0001, respectively), and RV diastolic area (overall P < 0.0001) increased during the season. Conversely, RV outflow tract did not vary (overall P = 0.96). During the season, no significant differences were observed in RV diastolic functional indexes and in RV fractional area change (overall P = 0.35). Global RV longitudinal strain did not significantly change (overall P = 0.52), although apical longitudinal strain significantly increased (overall P = 0.017). In association, left ventricular (LV) volume and mass increased during the season (overall P = 0.007). On multivariate analysis, LV mass was the only independent predictor of RVEDD at pre-season (β = 0.69, P < 0.0001) and at end-season (β = 0.82, P < 0.0001). Right ventricular chamber size increases during the competitive season in top-level athletes, with no significant changes in the outflow tract. RV morphological adaptation in top-level athletes practicing team sports is not associated with a reduction in RV function or in myocardial deformation and occurs in close association with changes on the left ventricle, suggesting a physiological remodelling of the right ventricle.