Cardiac Remodeling in Elite Aquatic Sport Athletes

Objective: To characterize and compare the sport-specific cardiac structure of elite swimmers (SW), water polo players (WP), and artistic swimmers (AS). Design: A cross-sectional assessment of elite aquatic athletes' hearts. Setting: The athletes' village at the 2019 FINA World Championships. Participants: Ninety athletes from swimming (SW) (20 M/17 F), water polo (WP) (21 M/9 F), and artistic swimming (AS) (23 F). Assessment and Main Outcome Measures: An echocardiographic assessment of cardiac structure was performed on noncompetition days. Results: Male SW displayed primarily eccentric volume-driven remodeling, whereas male WP had a greater incidence of pressure-driven concentric geometry (SW = 5%, WP = 25%) with elevated relative wall-thickness (RWT) (SW = 0.35 +/- 0.04, WP = 0.44 +/- 0.08, P < 0.001). Female SW and WP hearts were similar with primarily eccentric-remodeling, but SW and WP had greater concentricity index than artistic swimmers (SW = 6.74 +/- 1.45 g/(mL)(2/3), WP = 6.80 +/- 1.24 g/(mL)(2/3), AS = 5.52 +/- 1.08 g/(mL)(2/3), P = 0.007). AS had normal geometry, but with increased posterior-wall specific RWT (SW = 0.32 +/- 0.05, AS = 0.42 +/- 0.11, P = 0.004) and greater left atrial area than SW (SW = 9.7 +/- 0.9 cm(2)/m(2), AS = 11.0 +/- 1.1 cm(2)/m(2), P = 0.003). All females had greater incidence of left ventricular (LV) posterior/septal wall-thickness >= 11 mm than typically reported (SW = 24%, WP = 11%, AS = 17%). Conclusions: Male athletes presented classic sport-specific differentiation, with SW demonstrating primarily volume-driven eccentric remodelling, and WP with greater concentric geometry indicative of pressure-driven remodeling. Female SW and WP did not display this divergence, likely because of sex-differences in adaptation. AS had unique LV-specific adaptations suggesting elevated pressure under low-volume conditions. The overall incidence of elevated wall-thickness in female athletes may point to an aquatic specific pressure-stress.