A Comprehensive Echocardiographic Guide for Mitral Valve Repair - A Narrative Review

In patients with severe mitral regurgitation (MR), mitral valve repair is the preferred and recommended treatment; thus, precise diagnosis of the mechanism, location, and the specific scallop causing MR is decisive and paramount. Occasionally, mitral valve repair is inadequate (residual MR), or result in mitral stenosis, or is associated with systolic anterior motion (SAM) of the mitral valve and left ventricular outflow tract obstruction. Two- and three-dimensional Transesophageal echocardiography (2D and 3D TEE) can precisely diagnose the mechanisms, location and scallops causing MR, identify the mechanisms of repair failure, identify the predictors of SAM, and help decide when to return to bypass and address the residual lesion. The review comprehensively describes 2D and 3D TEE imaging methods relevant for evaluating the mechanisms of MR, identification of the location of MR, and the predictors of SAM prior to valve repair; and describes imaging methods to identify the presence of mitral stenosis and SAM post-repair. Further, the review discusses the importance of more-than-mild residual MR, describes the evaluation of residual MR and discusses pitfalls in differentiating mild and more- than-mild residual MR.