Mechanistic insights into atrial functional mitral regurgitation: Far more complicated than just left atrial remodeling.

Recent studies lend credibility to the notion that lone atrial fibrillation (AF) can cause functional mitral regurgitation (MR), commonly referred to as atrial functional MR (AF-MR). The conventional view holds that left atrial enlargement associated with AF causes annular dilatation which gradually moves the mitral valve leaflets apart resulting in inadequate coaptation and regurgitation. Recent findings, however, suggest that AF-MR is not solely related to left atrial remodeling, but that important structural and functional abnormalities of the left ventricle also play a role in its pathogenesis.