[Large ostium secundum atrial septal defect discovered after severe mitral regurgitation. A case report]

Mitral regurgitation is associated with ostium secundum atrial septal defect in about 22% of cases. mitral valve prolapse induced by atrial shunt is the main cause of this regurgitation. Ususually, atrial septal defect discovery precedes that of mitral regurgitation. The aim of this paper is to focus on clinical, hemodynamic and evolutive details of atrial septal defect and mitral regurgitation association. We report the case of large atrial septal defect in 37 years old girl referred for hemodynamic investigation of mitral regurgitation. The divergence of clinical data, electrocardiogram and echocardiography findings has led to atrial septal defect discovery. Hemodynamic data showed severe pulmonary arterial hypertension (medium pulmonary arterial pressure: 45 mmhg). Hence, mitral valve substitution by mechanical prosthesis and closure of atrial septal defect have been carried out. Ten hours after surgery, death occurred because of severe pulmonary arterial hypertension and heart failure.

Association of severe mitral regurgitation and large ostium secundum atrial septal defect is an original anatomo-clinic entity caracterized by mitral valve lesions diversity and severe secondary pulmonary arterial hypertension. Danger of such a hypertension is due to progressive and infra clinical rise of pulmonary resistances and association of increased pulmonary blood flow and capillary pulmonary hypertension.