Mitral Valve Stenosis | Diagnosis & Treatment

How is mitral valve stenosis diagnosed?

The process of arriving at a diagnosis of mitral valve stenosis usually involves several steps. Often, a clinician will first notice that your child has a heart murmur.

An echocardiogram (cardiac ultrasound) is the definitive test used to confirm the diagnosis. Other tests your child’s clinician might order to make, or rule out, a diagnosis of mitral valve stenosis can include:

How is mitral valve stenosis treated?

Routine monitoring

Children with mild to moderate mitral valve stenosis may not need any treatment other than routine monitoring, as long as they are displaying no outward symptoms and their daily lives are not affected by the condition.

Your child's cardiologist will regularly evaluate your child for any sign of further narrowing in the mitral valve and related complications. Most often, routine monitoring will involve physical examinations and echocardiograms.


Medication is not a cure for mitral valve stenosis but can be helpful in managing specific symptoms. In some cases, your child's clinician may prescribe medication to:

  • help the heart maintain healthy function and blood flow
  • control blood pressure
  • prevent abnormal heart rhythms, called arrhythmias

A child with mitral valve stenosis may also need to periodically take antibiotics in order to prevent an infection called bacterial endocarditis, even if the valve has been surgically replaced. Bacterial endocarditis can cause serious damage to the inner lining of the heart and its valves. Always let medical personnel know about your child's mitral valve stenosis before making arrangements for a medical procedure, even if the procedure seems minor or unrelated to your child's cardiac care.

Interventional catheterization/balloon valvuloplasty

Boston Children's Hospital has a program dedicated to interventional catheterization, the use of a thin tube called a catheter that is threaded from a vein or artery into the heart. We consider interventional catheterization the preferred way (vs. surgery) to treat children with mitral valve stenosis.

The most common interventional catheterization procedure used to treat mitral valve stenosis is balloon dilation or balloon valvuloplasty. With the child under general anesthesia, a small, flexible catheter is inserted into a blood vessel, most often in the groin. Using tiny, highly precise cameras and tools, clinicians guide the catheter up into the inside of the heart and across the mitral valve. A deflated balloon at the tip of the catheter is inflated once the tube is in place, and this balloon stretches the mitral valve open, reversing the problematic narrowing.

Valve-replacement surgery

For children with severe mitral stenosis, balloon valvuloplasty may not adequately fix the narrowed valve. In other cases, as a child grows, a mitral valve that was previously treated successfully with one or more balloon dilation procedures begins to narrow again, adding strain to the heart and affecting blood flow throughout the body. Repair of replacement of the mitral valve is the next step in treatment for these children.

If valve repair is not possible, cardiac surgeons will remove the damaged mitral valve and replace it with either:

  • a mechanical valve
  • a donor valve taken from a human or animal donor (sometimes, new valves can even be fashioned from the child's own tissue)

What is the long-term outlook for mitral valve stenosis?

Both types of valve-replacement surgery have an excellent success rate and a low incidence of complications. Children who have either procedure are likely to enjoy normal, healthy lives with minimal to no restrictions when playing sports or engaging in other strenuous activities.