Photo Credit: AI

The following is a summary of “Impact of Exercise on Atrial Functional Mitral Regurgitation and Its Determinants: An Exercise Echocardiographic Study,” published in the February 2025 issue of Cardiology by Schutter et al.

Atrial functional mitral regurgitation (AFMR) is a distinct form of MR observed in patients with AF and heart failure with preserved ejection fraction (HFpEF), but its pathophysiology remains poorly understood. Moreover, the severity of acute exercise’s impact on AFMR is not well-documented. This study aimed to investigate the effect of exercise on the severity of AFMR and to identify the key determinants contributing to its progression. Researchers enrolled 47 patients, including 39 with HFpEF and 22 with AF. Echocardiographic assessments were performed at rest and during maximal exercise to evaluate AFMR severity, mitral annular dimensions, left atrial size, systolic and diastolic function, and other relevant parameters. 

A significant increase in AFMR severity of ≥1 grade was noted in 20 patients (43%) during exercise, with this progression being associated with impaired progression of peak mitral annulus systolic velocity (Med S’) and an increase in systolic mitral annular diameter during exercise. In contrast, patients who did not experience worsening of AFMR showed a decrease in systolic annular diameter. Additionally, patients with moderate or severe AFMR during exercise (n=19, 40%) exhibited lower Med S’, larger systolic mitral annular diameters, reduced tricuspid annular plane systolic excursion, and more severe tricuspid regurgitation compared to those with mild AFMR during exercise. 

These findings suggest that AFMR is a dynamic condition that may worsen during exercise, with the deterioration of AFMR linked to impaired LV longitudinal contractile reserve and increased mitral annular dimensions. As left ventricular longitudinal function may influence mitral annular dynamics, these results support the hypothesis that AFMR arises from an imbalance between the mitral annulus area and leaflet area, caused by both annular dilation and impaired mitral annular dynamics. Therefore, exercise-induced worsening of AFMR could be due to the complex interplay between mitral annular dilation and reduced LV function, further complicating the pathophysiology of this condition.

Source: sciencedirect.com/science/article/abs/pii/S0002914925000013