Mitral regurgitation.

Mitral regurgitation (MR) is increasingly prevalent and poses an important public health problem. There are several mechanisms through which MR can occur. Primary (organic) MR is due to intrinsic valvular disease, whereas secondary (functional) MR is due to disruption of an otherwise normal mitral apparatus because of abnormal ventricular geometry. Identification of the causative mechanism is important as this will dictate management strategy and may influence subsequent outcome. Careful assessment of MR severity is important with the use of quantitative measures. There is currently no effective medical treatment for chronic MR. Careful follow-up is paramount in the management of MR to accomplish timely surgical intervention. Mitral valve repair is preferable to valve replacement. In chronic primary MR, conventional timing of surgery is based upon appearance of symptoms and hemodynamic consequences of chronic volume overload. Optimal timing of surgery for asymptomatic patients with chronic severe MR remains controversial although there is an increasing trend toward earlier surgery. In recent years there have been significant advances in percutaneous valve interventions for MR. Although initial results are promising, longer term evaluation will answer questions concerning efficacy, durability, and safety of these interventions.