Exercise Dynamics in Secondary Mitral Regurgitation: Pathophysiology and Therapeutic Implications.

Secondary mitral valve regurgitation (MR) remains a challenging problem in the diagnostic workup and treatment of patients with heart failure. Although secondary MR is characteristically dynamic in nature and sensitive to changes in ventricular geometry and loading, current therapy is mainly focused on resting conditions. An exercise-induced increase in secondary MR, however, is associated with impaired exercise capacity and increased mortality. In an era where a multitude of percutaneous solutions are emerging for the treatment of patients with heart failure, it becomes important to address the dynamic component of secondary MR during exercise as well. A critical reappraisal of the underlying disease mechanisms, in particular the dynamic component during exercise, is of timely importance. This review summarizes the pathophysiological mechanisms involved in the dynamic deterioration of secondary MR during exercise, its functional and prognostic impact, and the way current treatment options affect the dynamic lesion and exercise hemodynamics in general.