mitral valve stenosis

mitral valve obstruction can either be due to a supravalvar ring close to the valve orifice obstructing mitral flow, or to papillary muscle abnormality. a parachute mitral valve is where the papillary muscles are fused or one is severely hypoplastic. mitral valve anomalies are uncommon in children. mitral stenosis may occur as an isolated lesion but is much more common in association with other left heart obstructive disease such as coarctation, aortic or subaortic stenosis. in the latter situation, sometimes known as shone’s syndrome, mitral stenosis is often not revealed until after the obstruction in the arch and left ventricular outflow tract (lvot) are relieved. if mitral stenosis is severe in early life, the neonate will present with congestive cardiac failure or failure to thrive. removal of a supravalvar ring or mobilization of the papillary muscles may be attempted. this is not always successful and mitral valve replacement may be necessary. valve replacement is problematic in children as an artificial valve has to be replaced with growth and anticoagulants are necessary.