Mitral valve dysplasia syndrome: a unique form of left-sided heart disease

Mitral valve dysplasia syndrome is a unique form of left-sided heart disease characterized by aortic outflow hypoplasia, dilated left ventricle, dysplastic/incompetent mitral valve, and a restrictive/intact atrial septum. Patients with this constellation of abnormalities have been managed in a variety of ways with overall poor outcomes.

We performed a retrospective review of all patients with mitral valve dysplasia syndrome to identify fetal echocardiographic markers predictive of outcomes.

Mitral valve dysplasia syndrome was identified in 10 fetuses. Fetal left heart dilation and abnormal pulmonary venous flow were associated with increased mortality. Seven fetuses had abnormal pulmonary venous Doppler patterns; 3 had a unique "double-reversal" flow pattern. Severe fetal left heart dilation (left heart/right heart area ratio > 1.5) was present in 5. Prenatal intervention was performed on 3 fetuses: balloon aortic valvuloplasty (n = 2) and balloon atrial septostomy (n = 1). Of the 3, one died in utero and neither survivor underwent a 2-ventricle repair. Five patients required an immediate postnatal intervention to open the atrial septum. The overall mortality was 50%.

Mitral valve dysplasia syndrome is a unique form of congenital heart disease with severe aortic stenosis but normal or enlarged left ventricle secondary to primary mitral valve disease. Increased left heart size and pulmonary vein Doppler patterns are predictive of postnatal outcome. Despite the presence of a dilated left ventricle, postnatal management with staged single ventricle palliation may be the most effective strategy.