Mitral Valvular-Ventricular Interactions: Relative Importance and Clinical Implications

An understanding of the numerous ways in which the mitral valve supports left ventricle (LV) function is important to clinicians who evaluate interventions on the mitral valve. Knowledge of the relative contributions to LV function provided by the various support mechanisms allows clinicians to balance the benefits against the adverse effects of mitral interventions. Although much of the research into the valvular-ventricular interaction has been undertaken in animals with normal hearts, the known mechanics of the interaction can be logically translated to human cardiomyopathic hearts. The systolic force applied through the marginal chordae of the anterior mitral leaflet (AML) is the dominant mechanism supporting LV function, and any intervention that inhibits AML closure (immobilisation, splitting, partial resection, etc.) sacrifices some level of LV contractility. Such interventions might provide limited overall benefit in cardiomyopathic hearts that poorly tolerate further LV impairment. This narrative review presents a summary of the existing evidence on the relative contributions of the various valvular-ventricular support mechanisms and their clinical application.