The term “stenosis” describes an abnormal narrowing within a structure of the body. Mitral valve stenosis, therefore, describes the narrowing of the heart’s mitral valve.
To picture what happens when a child has mitral valve stenosis, it’s helpful to understand the basic anatomy of the heart. The diagram below shows the heart's internal structures (click to enlarge).
The parts of the heart affected by mitral valve stenosis are:
- the left atrium, one of two chambers that receive blood from veins in the body and then push the blood into the heart’s ventricles. The left atrium, as opposed to the right, receives oxygen-rich blood from the pulmonary veins and feeds this blood to the left ventricle.
- the left ventricle, one of two chambers that receive blood from the atria and then push that blood further along in the circulatory system. The left ventricle, as opposed to the right, receives oxygen-rich blood from the left atrium and pumps this blood out to supply the body.
- the mitral valve, a one-way valve with two flaps (called leaflets) that is located between the heart’s left atrium and left ventricle. The mitral valve closes when the ventricle pumps, preventing blood from backing up into the left atrium, and ensures that all of the blood moves out to the body.
When a child has mitral valve stenosis:
- blood flow from the left ventricle into the body is limited
- the left atrium may become enlarged due to the building pressure
- the lungs may become congested
- the heart may become weak over time
Here are some other important things to know about mitral valve stenosis:
- Many children with mitral valve stenosis do not show any outward symptoms, but some will experience rapid breathing or slow growth and weight gain.
- Often, mitral valve stenosis is caused by a heart defect present at birth.
- Children can also develop mitral valve stenosis as a complication of rheumatic fever, though the disease is rare in the United States.
- Children with more advanced mitral valve stenosis are likely to require interventional catheterization or valve surgery.
- However, some kids with mitral valve stenosis don’t need any immediate treatment. Many children do very well for a long time with regular monitoring by their treatment team.
- Mitral valve stenosis can affect each child differently. Your physician is the best resource for providing detailed information about your child’s individual situation and making recommendations about the treatment plan that best meets the needs of your child and your entire family.
What causes mitral valve stenosis in children?
Mitral valve stenosis in children is normally caused by either
- a birth defect, such as:
- a narrowed mitral valve
- a damaged or malformed mitral valve
Learn more about how Boston Children’s treats congenital heart defects.
- rheumatic fever, a complicated disease (one that is becoming increasingly rare in the United States) that can develop in children already suffering from an infection of streptococcus bacteria, like “strep throat” or scarlet fever. Rheumatic fever can lead to scarring of the leaflets that make up the mitral valve, causing the valve to become constricted and narrowed.
In a small number of cases, children develop mitral valve stenosis as a complication of a tumor or blood clot that obstructs the valve.
What are the symptoms of mitral valve stenosis?
Many children with mitral valve stenosis show no outward signs, since they are in the mild to moderate stages of the condition and their symptoms have not yet progressed to a more serious level. The only identifiable symptoms in most cases are rapid breathing, slow growth/weight gain or a soft heart murmur.
As mitral valve stenosis progresses, children may show one or more of these symptoms:
- rapid or labored breathing
- frequent coughing or wheezing
- slow growth/weight gain
- feeding difficulties
- frequent respiratory infections
- irregular heartbeats or heart palpitations
- chest pain
You should seek treatment from a qualified medical professional right away if you notice any of these warning signs in your child.
Q: Will my child be OK? How much will mitral valve stenosis disrupt her life?
A: Your child’s long-term health and course of treatment will depend greatly on her individual circumstances, especially:
- her age
- how narrowed the mitral valve has become at the time of diagnosis
- her tolerance for specific medications or procedures
- your family’s preferences for treatment
Children with mild or moderate mitral valve stenosis may not need any immediate treatment, and can do well for long periods of time with regular monitoring and checkups by their treatment team.
The most serious cases of mitral valve stenosis require interventional catheterization or surgical repair or replacement of the valve.
Q: Does my child need to take antibiotics before routine medical or dental procedures?
A: A child with mitral valve stenosis may need to periodically take antibiotics in order to prevent an infection called bacterial endocarditis bacterial endocarditis, even if his mitral valve has been surgically replaced. Bacterial endocarditis can cause serious damage to the inner lining of the heart and its valves.
Children with heart conditions like mitral valve stenosis may be vulnerable to developing endocarditis while undergoing medical procedures that could release bacteria into the bloodstream. In these cases, a regimen of antibiotics might be prescribed before the child has the procedure. You should 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.
If your child has mitral valve stenosis, but no other cardiac problems, he probably will not need antibiotics before a routine dental procedure (for example, a teeth-cleaning). Read the American Heart Association’s latest guidelines for dental patients with heart conditions (Adobe Acrobat required).
Q: Does my child have to cut back on physical activities?
A: Whether your child needs to cut back significantly on activities—or cut back at all—depends greatly on her age, how narrowed the mitral valve has become at the time of diagnosis and what symptoms (if any) she is experiencing.
A child with mild mitral stenosis may not need to change his daily activities, and can continue to take part in sports and recreational play. A child with more pronounced narrowing of the mitral valve may need to limit participation in activities that call for a higher level of exertion and physical endurance. In the most serious cases (as well as when a child is preparing to undergo interventional catheterization or valve repair or replacement), the child may need to eliminate certain high-impact, high-stress activities.
Your child’s treating clinician will evaluate her individual situation and advise you of any necessary restrictions or changes in physical activity.
Q: Is my child at serious risk of having a heart attack?
A: One of the most common misconceptions about mitral valve stenosis is that a child diagnosed with the condition is at high risk of a sudden heart attack.
Most children with mitral valve stenosis are diagnosed when they are still comfortable and free of outward symptoms. Thanks to available diagnostic procedures and imaging technology, the condition can be detected even when the only noticeable symptom is a soft heart murmur.
This ability to make an early diagnosis gives clinicians the opportunity to start monitoring kids with mitral valve stenosis right away, and to easily “stay on top of” the progression of the condition with regular echocardiograms and exams.
Newborns with critical mitral valve stenosis tend to have much more serious symptoms and much more severe narrowing of the valve at the time of diagnosis. However, sophisticated imaging and intervention procedures—including interventional catheterization and valve repair or replacement—enable clinicians to take immediate action.
Q: What do I need to look out for once my child has been diagnosed with mitral valve stenosis?
A: Parents of children with mitral valve stenosis should always be watchful for changes in behavior, appearance, activity level and respiration.
You should seek medical help immediately if your child experiences any of the following:
- heart palpitations or irregular heartbeat
- racing heartbeat
- painful coughing, especially with red- or pink-tinged discharge
- difficulty “catching a breath”
- rapid or shallow breathing
- high fever
- clammy skin or the feeling of a “cold sweat”
- pale, ashen color in the face
Q: Are there other, non-medical precautions I can take to help my child manage her mitral valve stenosis?
A: While it is essential that any child with mitral valve stenosis be treated by a qualified health professional, you and your family can help your child take steps to live a healthier life during treatment. These steps include:
- avoiding foods that are high in sodium (salt); too much sodium can elevate blood pressure and create additional strain on the heart
- avoiding caffeine, which can exacerbate arrhythmias (irregular heartbeats). Children should limit their intake of caffeinated beverages, like soda.
- maintaining a healthy weight; being overweight causes the heart and lungs to work harder
Q: Can Boston Children’s treat mitral valve stenosis when a baby is still in the womb?
A: Yes. Boston Children’s Fetal Cardiology Program can:
Learn more about these services and therapies.
Q: Is there a cure for mitral valve stenosis?
A: In general, mitral valve stenosis is a progressive condition, meaning that the valve will continue to narrow over time and further intervention will eventually become necessary.
The good news is that, even when mitral valve stenosis is advanced, interventional catheterization and surgical valve repair or replacement have excellent success rates for restoring normal heart function and blood flow.
Questions to ask your doctor
You and your family play an essential role in your child’s treatment for mitral valve stenosis. It’s important that you share your observations and ideas with your child’s treating physician, and that you have all the information you need to fully understand the treatment team’s explanations and recommendations.
You’ve probably thought of many questions to ask about your child’s mitral valve stenosis. It’s often very helpful to jot down your thoughts and questions ahead of time and bring them with you, along with a notebook, to your child’s appointment. That way, you will have all of your questions in front of you when you meet with your child’s treating clinician and can make notes to take home with you. (If your child is old enough, you can encourage him or her to write down questions, too.)
Initial questions to ask your doctor might include:
- How did you arrive at this diagnosis?
- Are there any other conditions my child might have instead?
- Does my child require further testing or procedures?
- How advanced is the mitral valve stenosis?
- What will this affect my child’s long-term health?
- What medications will you prescribe?
- What are the possible side effects of these medications?
- Is interventional catheterization necessary at this time?
- Will my child need valve replacement surgery?
- What role should I play in my child’s treatment?
- How should I talk to my child about this condition and the long-term outlook?
- How should I explain my child’s condition to others?
- Do I need to restrict my child’s physical activity?
- Does my child need to take antibiotics to protect against a bacterial infection?
- Do I need to make any other changes to my child’s home and school routines?
- What other resources can you point me to for more information?