Intense exercise exposes the heart to significant hemodynamic demands, resulting in adaptive changes in cardiac morphology and function. Nevertheless, the athletic adaptation of the atrioventricular valves remains to be elucidated. Our study aimed to characterize the geometry of mitral (MA) and tricuspid (TA) annuli in elite athletes using 3-D echocardiography. Thirty-four athletes presented with functional mitral regurgitation (FMR) were retrospectively identified and compared with 34 athletes without mitral regurgitation (MR) and 34 healthy, sedentary volunteers. 3-D echocardiographic datasets were used to quantify MA and TA geometry and leaflet tenting by dedicated softwares. MA and TA areas, as well as tenting volumes, were higher in athletes compared with controls. MA area was significantly higher in athletes with MR compared with those without (8.2 ± 1.0 vs. 7.2 ± 1.0 cm2/m2, P < 0.05). Interestingly, athletes with MR also presented with a significantly higher TA area (7.2 ± 1.1 vs. 6.5 ± 1.1 cm2/m2, P < 0.05). Nonplanar angle describing the MA's saddle shape was less obtuse in athletes without MR, whereas the values of athletes with MR were comparable with controls. The exercise-induced relative increases in left ventricular (35 ± 25%) and left atrial (40 ± 29%) volumes were similar; however, the increment in the MA area was disproportionately higher (63 ± 23%, overall P < 0.001). The relative increase in TA area (40 ± 23%) was also higher compared with the increment in right ventricular volume (34 ± 25%, P < 0.05). Atrioventricular annuli undergo a disproportionate remodeling in response to regular exercise. Athletic adaptation is characterized by both annular enlargement and increased leaflet tenting of both valves. There are differences in MA geometry in athletes presented with versus without FMR.NEW & NOTEWORTHY We have characterized the annular geometry of mitral and tricuspid valves in elite athletes using 3-D echocardiography. We have found that exercise-induced remodeling of the atrioventricular annuli comprises a disproportionate dilation of annular dimensions and increased leaflet tenting of both valves. Moreover, we have demonstrated a more pronounced saddle shape of the mitral annulus in athletes without mitral regurgitation, which was not present in those who had mild regurgitation.
Keywords: 3-D echocardiography; athlete’s heart; functional mitral regurgitation; mitral annulus; tricuspid annulus.