The mitral valve is located on the left side of the heart, between two chambers—the atrium and the ventricle. In mitral valve stenosis, also known as mitral stenosis, the mitral valve opening is narrowed. This means that not enough blood can flow through it, which can lead to a variety of issues, including fatigue, blood clots, and heart failure.
Mitral valve stenosis is usually a congenital heart defect meaning it is present at the time of birth. Around eight in every 1000 babies born have some type of congenital heart defect. Even if the mitral valve is the main problem, some children with this condition have other abnormalities on the left side of the heart, perhaps in the aortic valve area or in the aorta as it leaves the heart.
Causes of Mitral Valve Stenosis
The heart is formed early in pregnancy, but doctors do not fully understand why some children’s hearts do not develop properly. For the majority of babies born with mitral valve stenosis, doctors may never find a cause. However, one reason may be if one or both parents had a congenital heart defect.
There are several potential causes of mitral valve stenosis. Causes of this condition include:
- Rheumatic fever: A complication of strep throat, rheumatic fever can damage the mitral valve. Rheumatic fever is the most common cause of mitral valve stenosis. It can damage the mitral valve by causing the flaps to thicken or fuse. Signs and symptoms of mitral valve stenosis might not show up for years.
- Calcium deposits: As you age, calcium deposits can build up around the ring around the mitral valve (annulus), which can occasionally cause mitral valve stenosis.
- Other causes: In rare cases, babies are born with a narrowed mitral valve (congenital defect) that causes problems over time. Surgery is usually recommended to repair congenital mitral stenosis.
- Other rare causes include radiation to the chest and some autoimmune diseases, such as lupus.
Symptoms of Mitral Valve Stenosis
Many children with mitral valve stenosis show no signs of the condition. Because of the fact that mild to moderate stages of the condition may not have progress enough, a child’s symptoms may not show until the condition has progressed to a more serious level. In most cases, the symptoms that are most identifiable are rapid breathing, slow growth/weight gain or a soft heart murmur.
As mitral valve stenosis progresses, children may show the following symptoms:
- Rapid breathing
- Frequent coughing or wheezing
- Slow growth or weight gain
- Feeding difficulties
- Frequent respiratory infections
- Irregular heartbeats or heart palpitations
- Chest pain
Mitral Valve Stenosis Diagnosis
Typically, there are several steps involved in diagnosis mitral valve stenosis. Many times, a doctor will first notice your child has a heart murmur. Heart murmurs can be detected with a stethoscope during a routine physical examination or with an electrocardiogram (EKG or ECG).
The loudness of the murmur, where in the chest it is best heard and the types of noise it causes (such as gurgling or blowing) will all give your child’s doctor a better idea of the nature of your child’s heart problem.
An echocardiogram is the definitive test used to confirm the diagnosis of mitral valve stenosis. An echocardiogram is a special procedure that uses ultrasonic sound waves to create images of the heart and its structures. Echocardiograms are painless, do not require an IV and only take about an hour to perform.
Other tests your child’s doctor might order to make a diagnosis may include:
- Chest X-ray
- Cardiac MRI
- Cardiac catheterization
Treatment of Mitral Valve Stenosis
Mitral valve stenosis can affect every child differently. Treatment will depend on the severity of the stenosis and can involve monitoring, medication, and/or surgery.
In the short term, children with mild to moderate mitral valve stenosis may not need any treatment other than routine monitoring by his or her doctor. As long as the child is not displaying symptoms, no treatment may be necessary.
Medication is not a cure for mitral valve stenosis, but can be helpful in managing specific symptoms. In some cases, your child's doctor may prescribe medication to:
- Help the heart maintain healthy function and blood flow
- Control blood pressure
- Prevent abnormal heart rhythms (arrhythmias)
Balloon valvuloplasty is performed while your child is under a general anesthetic, which means your child will be asleep during the procedure
Valve Replacement Surgery is more invasive option to replace the mitral valve. This is the next step in treatment for children whose balloon valvuloplasty procedure is not adequate. As a child grows, it is possible the original procedure will need to be repaired as well.
During valve replacement, the surgeon will remove the damaged mitral valve and replace it with either a mechanical valve (made of ceramic or other synthetic materials) or a donor valve from a human or animal.
Whether your child receives a mechanical valve or a donor valve, both have an excellent success rate and a low incidence of complications. After the procedure, children are likely to enjoy normal, healthy lives with minimal to no restrictions on playing sports or engaging in other strenuous activities.