Eclipsed Mitral Regurgitation: Paroxysmal Reversible Severe Mitral Regurgitation Presenting with Recurrent Pulmonary Edema: A Case Report.

Eclipsed mitral regurgitation (MR) is a rare, paroxysmal entity with preserved left ventricular ejection fraction, marked by abrupt, severe, but reversible MR that is demonstrable only during episodes. We report the case of an 82-year-old woman with systemic sclerosis and persistent atrial fibrillation who had four admissions for acute heart failure within six months. Transthoracic echocardiography captured massive MR with leaflet malcoaptation, severe pulmonary hypertension, a dagger-shaped MR jet, and a blood pressure drop; between episodes, MR was mild and leaflet coaptation was normal, and provocation testing was negative. Recurrent events during hospitalization prompted urgent surgery. Mitral valve replacement with concomitant tricuspid annuloplasty prevented recurrence, and the postoperative course was uneventful until death from tuberculosis-related sepsis. Operative inspection showed minimal structural change of the mitral valve, and histopathology demonstrated preserved leaflet architecture with mild fibrosis and myxomatous change, indicating no significant intrinsic valvular damage. These findings indicate that eclipsed MR is a unique pathophysiological entity.