Atrial functional mitral regurgitation.

PURPOSE OF REVIEW To review the prevalence and prognosis of atrial functional mitral regurgitation (AFMR), the distinctive echocardiographic and mechanistic findings, and the therapeutic implications of this newly described disorder. RECENT FINDINGS Initial studies identified an association between atrial fibrillation, mitral annular dilation, and significant mitral regurgitation despite a normal mitral valve and left ventricle. Accumulating data suggest that AFMR is not rare and may have a prognosis as poor as functional MR associated with LV remodeling. Echocardiography has played an important role in understanding the unique pathophysiology of AFMR, and proposed mechanisms include not only atrial remodeling, but structural and functional abnormalities of the LV (HFpEF shares a common pathophysiology) and insufficient leaflet growth. Timely rhythm control of atrial fibrillation and strategies that reduce diastolic pressure, left atrial and mitral annular enlargement, and that favorably affect mitral leaflet adaptation, are promising preventive and treatment options that warrant clinical study. SUMMARY Functional mitral regurgitation may be atrial in origin and should be considered in patients with (particularly long-standing) atrial fibrillation and in those with HFpEF.