Aortic Valve Stenosis

What is aortic valve stenosis?

The term “stenosis” describes an abnormal narrowing within a structure of the body. Aortic valve stenosis, therefore, refers to the narrowing of the heart’s aortic valve, a one-way valve located between the left ventricle — the pump that pushes blood out to the body — and the aorta, the major blood vessel that carries blood to different parts of the body.

When a child has aortic valve stenosis, the leaflets (tiny flaps of tissue) that make up the aortic valve get stuck and can’t separate fully. This causes a problematic blockage that increases the pumping work of the left ventricle, and may lessen the amount of blood that goes out of the ventricle to the body through the aortic valve. This extra work can weaken the heart over time.

Some children with aortic valve stenosis don’t need immediate treatment, and those with no outward symptoms can do very well for a long time with only regular monitoring by their care team. However, children with more advanced aortic valve stenosis are likely to require interventional catheterization, valve repair or replacement surgery. 


What are the types of aortic valve stenosis?

The condition is classified according to its severity: mild, moderate, severe or critical.

Mild aortic valve stenosis

A child with mild aortic valve stenosis has very limited narrowing within the valve. These children will not show any outward symptoms; the only detectable problem is a pronounced, easily identified heart murmur. Children with this mild type of aortic valve stenosis are otherwise healthy and able to go about their daily lives without disruption.

Moderate aortic valve stenosis

Children with moderate aortic valve stenosis have a slightly more significant narrowing of the aortic valve, but usually show no outward symptoms and are otherwise healthy. A child with this type will have an easily detected and identified heart murmur. 

Severe aortic valve stenosis

A child with severe aortic valve stenosis has such an advanced degree of narrowing in the valve that the left ventricle may become very stiff and may not function properly. Interventional catheterization with balloon dilation or valve repair or replacement surgery are necessary to treat severe aortic valve stenosis.

Critical aortic valve stenosis

This, the most serious type of aortic valve stenosis, is usually present at birth. The newborn’s aortic valve is so narrowed that the heart cannot pump enough blood to nourish the body, so immediate intervention is needed — usually by interventional catheterization with balloon dilation or by surgically replacing the aortic valve.

How we care for aortic valve stenosis

The Boston Children's Hospital Benderson Family Heart Center team has years of expertise in treating all types of heart defects and heart disease, with specialized understanding of problems like aortic valve stenosis that affect the valves of the heart.

We treat every stage of aortic valve stenosis in children, adolescents and adults, as well as babies in utero in our Fetal Cardiology Program. We use minimally invasive techniques whenever we can and are committed to repairing a child's own valve rather than resorting to an entire valve replacement whenever possible.