Aortic Stenosis (AS)

Congenital stenosis of the aortic valve is the most common form of LVOT obstruction in the neonate or infant.  They will often have a “unicuspid” valve orifice with no appreciable leaflets.  The valve itself may be normal, as in supravalvar aortic stenosis, which is associated with Williams syndrome (Chromosome 7). Diagnosis is by echocardiography.  They present with profound congestive heart failure and cyanosis.  Balloon dilation and operative valvotomy or transventricular dilation have similar risks and their use varies by institution.

Older children with valvar AS usually have a bileaflet valve with fused commissures.  They may have exercise intolerance, angina, and syncope or near-syncope.  Operation is indicated for a symptomatic child with echocardiography showing a transvalvar gradient > 40 mmHg, LVH, or ischemia, or an asymptomatic patient with gradient > 50-75 mmHg.  Open surgical valvotomy is effective for most children with congenital valvar AS, although at least half of patients will require subsequent reoperation.  Valve replacement (the Ross procedure) is seldom necessary except in patients with severe aortic insufficiency or for rheumatic heart disease.