Dynamic changes of mitral annulus in patients with degenerative mitral regurgitation and chronic atrial fibrillation undergoing mitral valve reconstruction

Objective This study was designed to assess structural and dynamic changes in the mitral annulus in patients before mitral valve reconstruction for degenerative mitral regurgitation with or without chronic atrial fibrillation. Methods One hundred and fifty one consecutive patients undergoing mitral valve reconstruction for mitral regurgitation due to myxomatous disease between July 2013 and May 2016 were included. Of these, 117 had a sinus rhythm (SR group) and 34 had chronic AF (AF group). Patients who underwent aortic surgery and were found to have no underlying cardiac valve disease nor coronary artery disease were included as the control group (n = 20). Real-time three-dimensional trans-esophageal echocardiography (3D-TEE) was used to assess mitral annulus shape, size, and movements. Results Annular areas in the control group were the smallest of the three groups and changed considerably through the cardiac cycle. Mean anteroposterior and intercommissural diameter measurements in the SR group were significantly larger but oscillated less than in the control group. Those diameters were the largest in the AF group and oscillated very little. Dilatation of the annulus in the AF and SR groups was accompanied by flattening and marked loss of oscillation in the height-to-intercommissural-width ratio which should peak in early systole. Conclusions In patients with degenerative mitral regurgitation undergoing mitral valve surgery, preoperative chronic atrial fibrillation is associated with more progressed annular remodeling, characterized by marked enlargement of annular area, circumference, and anteroposterior diameter.