Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation

• Published in: Journal of the American College of Cardiology 2022-12, Vol.80 (24), p.2314-2330
• Main Authors: Farhan, Serdar, Silbiger, Jeffrey J., Halperin, Jonathan L., Zhang, Lily, Dukkipati, Srinivas R., Vogel, Birgit, Kini, Annapoorna, Sharma, Samin, Lerakis, Stamatios
• Format: Article
• Language: English
• Subjects: atrial fibrillation; atrial functional mitral regurgitation; atrial functional tricuspid regurgitation; atriogenic leaflet tethering; hamstringing; mitral annulus
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2022.09.046

The conventional view holds that functional mitral regurgitation (MR) is caused by restriction of leaflet motion resulting from displacement of the papillary muscle-bearing segments of the left ventricle. In the past decade, evidence has accrued suggesting functional MR can also be caused by left atrial enlargement. This underrecognized cause of secondary MR—atrial functional MR (AF-MR)—is mechanistically linked to annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering. AF-MR has been described in patients with atrial fibrillation and heart failure with preserved ejection fraction. Preliminary data suggest rhythm control may decrease MR severity in patients with atrial fibrillation. Additionally, several studies have reported reductions in MR and symptomatic improvement with restrictive annuloplasty and transcatheter edge-to-edge repair. This review discusses the pathophysiology, echocardiographic diagnosis, and treatment of AF-MR. AF-tricuspid regurgitation is also discussed. [Display omitted] •Atrial functional MR is an underrecognized cause of secondary MR.•Atrial fibrillation and HFpEF are associated with atrial functional MR.•Preliminary evidence suggests that rhythm control may reduce the severity of AF-MR, but further studies are needed.