Mechanisms and pathophysiology of mitral valve regurgitation

The mitral valve (MV) is a sophisticated natural engineering marvel. The MV requires coordinated action of all its interrelated anatomical components: The MV leaflets, the annulus, the left atrium, the tendinous chords and the papillary muscles with its surrounding left ventricular wall for an effective closure of its orifice. Mitral valve regurgitation (MR) is frequently found in patients undergoing cardiac surgery with cardiopulmonary bypass. MR can be secondary to a structural or a functional defect of one or several components of the MV. The mechanism(s) of functional MR is the most complex. A precise understanding of the pathophysiology of MR helps resolving the cardiac status of a patient and choice of therapy for a particular patient. Transesophageal echocardiography can define the underlying mechanism(s) of MR; a thorough understanding of the mechanism(s) helps deciding the surgical procedure needed to repair the MR. In this article, the author reviews the mechanisms and pathophysiology of MR