Atrial Functional Mitral and Tricuspid Regurgitation

Functional or secondary regurgitation of the atrioventricular valves most commonly presents as a consequence of ventricular heart disease. However, there is increasing recognition that functional mitral and/or tricuspid regurgitation can also relate to isolated atrial pathology in the absence of ventricular disease, as seen in atrial fibrillation (AF) and/or heart failure with preserved ejection fraction (HFpEF). The aim of this review article is to summarize recent data and insights into the mechanisms, diagnosis, and therapeutic options of atrial functional mitral regurgitation (AFMR) and atrial functional tricuspid regurgitation (AFTR). Isolated annular dilation and dysfunction resulting in central leaflet malcoaptation is thought to be the culprit mechanism underlying AFMR and AFTR, as opposed to “ventricular” functional regurgitation caused by global or regional ventricular dilation, leaflet tethering, and annular dilation due to chronic volume overload. Both AF and HFpEF have been associated with the presence of AFMR and AFTR, which is associated with worse outcome. AFTR is more common in an elderly population with persistent AF. Rhythm control strategies have shown to be effective in reducing atrial functional regurgitation. The role of surgical and interventional repair strategies for treatment of AFMR or AFTR has yet to be determined. AFMR and AFTR are clinically distinct forms of functional atrioventricular regurgitation, rooted in atrial remodeling and isolated annular dilation. Because of their peculiar pathophysiology, both entities might benefit from a different approach compared with functional regurgitation in the setting of ventricular disease. The burden of AFMR and AFTR is expected to increase substantially in our aging population with increasing prevalence of AF and HFpEF.