Mitral Valve Abnormalities

What are mitral valve abnormalities?

The mitral (pronounced MY-trahl) valve acts like a door in the heart. It allows blood to pass from the left atrium (which receives blood from the lungs) to the left ventricle (which pumps blood out to the body). The mitral valve has 2 flaps, also called leaflets.

There are 3 different kinds of abnormalities of the mitral valve: 

  • Mitral valve prolapse is when 1 or both valve flaps don’t close smoothly and may not seal tightly when the heart pumps. Instead, they may collapse backward into the left atrium. This sometimes causes regurgitation.
  • Mitral valve regurgitation is when the mitral valve does not close well, which allows blood to leak back from the left ventricle into the left atrium. This may cause the atrium to get bigger. Then it cannot squeeze as effectively as it should.
  • Mitral valve stenosis is when the valve becomes narrow or tight. This makes it hard for the blood to get from the left atrium to the left ventricle. As a result, blood can back up in the blood vessels of the lungs. Valve stenosis and regurgitation can happen together.
  • Some children begin life with a normal mitral valve and then develop problems later on. One cause of mitral valve problems is rheumatic fever, a problem with inflammation that can develop after an infection with Streptococcus bacteria.

    Some children are born with mitral valve problems. In many situations, the cause isn’t clear. Children born with mitral valve problems usually have other abnormalities that need to be treated: 

    • Congenital mitral valve regurgitation often occurs in children who have holes in the walls of the heart that divide the upper or lower heart chambers.
    • Congenital mitral valve narrowing (stenosis) is usually seen in association with abnormalities that cause obstruction to blood flow on the left side of the heart. Rarely, mitral valve narrowing can occur as an isolated condition.
    • Sometimes children may have other health conditions at birth, too. For instance, mitral valve prolapse sometimes occurs with Marfan syndrome, and some types of mitral regurgitation are common in children with Down syndrome. 

    Some valve abnormalities don’t cause any problems. Others can cause serious problems, like heart failure, if they aren’t treated.

Mitral Valve Abnormalities at Seattle Children’s


  • With more than 40 pediatric cardiologists, we have experience diagnosing and treating every kind of heart problem.

    Our heart team has treated many children with mitral valve abnormalities. In a typical year, we see dozens of children with these conditions. We have extensive experience with the treatment these patients may require, including cardiac catheterization and surgery to repair or replace abnormal mitral valves. We also have a pediatric cardiac anesthesia team and a Cardiac Intensive Care Unit to help care for children who have heart surgery.

    See our statistics and outcomes for mitral valve abnormalities repair and replacement.

    Seattle Children’s has been treating children since 1907. Our team members are specially trained in their fields and in meeting the unique needs of children. For example, each of our heart surgeons is board certified in pediatric cardiac surgery. This means they have over 12 years of training in how to take care of kids. Our child life specialists know how to help children understand their illnesses and treatments in ways that make sense for their age.

  • When you come to Seattle Children’s, a whole team of people work together to care for your child. Along with your child’s heart doctor (cardiologist), you are connected with the entire heart center team, including cardiac surgeons, cardiac anesthesiologists and cardiac intensivists.

    We also have available every conceivable medical and surgical specialist who might be needed to care for your child. But it doesn’t stop there. We have an outstanding team of nurses, nurse practitioners, child life specialists and social workers, all working together to meet all of your child’s health needs and help your family through this experience.

    Read more about the supportive care we offer.

    We’re committed to your child’s overall health and well-being. We’ll discuss treatments in ways you can understand and involve you in every decision.

Symptoms of Mitral Valve Abnormalities

Mitral valve abnormalities may cause no symptoms for many years.

Your child may have some of these symptoms, depending on the valve problem and how severe it is: 

  • Feeling short of breath when active or lying down
  • Coughing
  • Feeling more tired than normal
  • Having palpitations
  • Having an arrhythmia
  • Fainting or feeling dizzy
  • Having chest pain

Diagnosing Mitral Valve Abnormalities

To diagnose a problem with the mitral valve, your doctor will examine your child. The doctor will use a stethoscope to listen for abnormal sounds in their heart (a murmur) or the sound of a valve not closing well. Sometimes doctors find valve problems after hearing a heart murmur in a child who appears well.

Your child will need an echocardiogram test so the doctor can see how their heart is working.

They may need other tests that provide more information about their heart. These include: 

Treating Mitral Valve Abnormalities

Treatment for mitral valve abnormalities depends on the type of problem and how it affects your child.

  • Most children with mitral valve prolapse don’t need treatment because their valve causes no symptoms or problems. If they do have symptoms, like palpitations or chest pain, they may need medicine to relieve these.

    In uncommon cases, when a prolapsed valve causes major regurgitation, a child may need surgery to repair or replace the valve.

  • Depending on how severe it is, this valve problem may be treated with medicine that helps the left ventricle pump better so less blood leaks back into the left atrium. If medicine does not help enough, your child may need surgery to repair or replace their mitral valve.

    Mitral valve regurgitation may lead to an arrhythmia. If this happens, your child may need medicines that help control their heartbeat.

  • If mitral valve stenosis is not treated, blood pressure in the lungs may get too high. This is called pulmonary hypertension. It can cause permanent damage to the lungs and the heart, including heart failure.

    To prevent damage, some children can have a procedure to open their mitral valve. This is done in the catheterization lab. A balloon is inserted through the valve. When the balloon is inflated, the valve is stretched open. Then the balloon is removed. This is called balloon valvuloplasty.

    Some children may need surgery to replace their mitral valve.

Helping Your Child Transition to Adult Care

To meet your child’s long-term healthcare needs, we have a special Adult Congenital Heart Disease Program to transition your child to adult care when they’re ready.

Contact Us 

Contact the Heart Center at 206-987-2515 to request an appointment, a second opinion or more information.

Providers, see how to refer a patient.