Mitral insufficiency and heart failure: The surgical point of view

Mitral valve regurgitation frequently accompanies the syndrome of congestive heart failure (CHF). Mitral valve regurgitation if often functional as it develops during the progression of the syndrome of CHF. Alternatively, mitral valve regurgitation is the primary event which leads to the syndrome of CHF by chronically exposing the left ventricle (LV) to volume overload. When managing patients with CHF and primary or functional mitral regurgitation, reduction of the regurgitant mitral volume is essential to interrupt the downward spiral which characterizes the failing LV exposed to volume overload. Surgical approaches to mitral valve regurgitation were formerly excluded when LV ejection fraction was below 40%. However, recent surgical techniques, including mitral valve repair and preservation of the mitral subapparatus, have led cardiac surgeons to attempt correction of mitral valve regurgitation in patients with CHF and LV ejection fractions well below 40%. In the first part of the review the pathophysiology of these various situations will be reviewed. The different clinical situations which involve both mitral regurgitation and congestive heart failure will be described. In the second part of the review the surgical approach to mitral valve regurgitation will be discussed. Different techniques of mitral valve repair as described in the pioneering work of Prof. A. Carpentier will be described. The importance of the preservation of the mitral subvalvular apparatus in mitral valve replacement is outlined. Finally, the last section of the manuscript will describe the use of intraoperative transesophageal echocardiography during mitral valve repair. The importance, specific conditions and pitfalls Of the technique will be discussed.