Patient education: Hypertrophic cardiomyopathy in children (The Basics)

What is hypertrophic cardiomyopathy? — Hypertrophic cardiomyopathy, or "HCM," is a condition that makes the heart muscle get too thick (figure 1). When this happens, it can keep the heart from pumping blood as well as it should. This can cause breathing problems, chest pain, and other symptoms.

HCM is usually caused by a genetic problem that runs in families.

What are the symptoms of HCM in children? — Some children show no symptoms. But others do.

People with HCM sometimes have a heart murmur. This is an extra sound that doctors or nurses hear when they listen to the heart with a stethoscope. A doctor or nurse might find a murmur during a routine exam, such as before a child starts playing sports.

Babies and young children might have symptoms, such as:

●Being much more tired than usual

●Breathing fast

●Having trouble feeding

Other children might not have any symptoms until their teen years. Symptoms can include:

●Feeling short of breath, especially during exercise

●Chest pain – This is often worse during exercise.

●Fainting or feeling like they might faint

●Heart palpitations – These feel like the heart is pounding, beating hard or fast, or skipping beats.

Are there tests for HCM? — Yes. Tests to check for HCM can include:

●Electrocardiogram ("ECG") – This test measures electrical activity in the heart (figure 2). An ECG can show if the heart is beating in a normal pattern and rhythm. An ECG can also show thickening of the heart muscle. The doctor might have your child exercise during the test.

●Echocardiogram ("echo") – This test uses sound waves to create a picture of the heart (figure 3). Doctors use it to see how thick the walls of the heart are, measure the spaces inside the heart, and see how well the heart pumps blood. The doctor might have your child exercise during the test or right before.

●Genetic testing – This can show if your child has one of the abnormal genes that some people with HCM have.

●Cardiac MRI – This test creates pictures of the heart. It can show parts of the heart that are hard to see with an echo.

If your child has HCM, other family members (siblings and parents) should get tested for it, too. Tests include a physical exam as well as an ECG and echo. Siblings usually need tests every year between ages 12 and 18. After age 18, most people only need to be tested once every 5 years. If your child has an abnormal gene, family members should get genetic testing to look for this, too.

Should my child see a doctor or nurse? — Call the doctor or nurse right away if your child has HCM and has any of the symptoms listed above. Symptoms can include trouble breathing, chest pain, fainting, or heart palpitations. Babies might have trouble feeding or gaining weight.

The doctor can do tests to see if your child needs treatment.

How is HCM in children treated? — If your child does not have symptoms, they probably will not need treatment. If symptoms happen, treatments include:

●Medicines to slow the heart rate and help the heart muscle relax

●A device called a "defibrillator" – This can sense and control abnormal heartbeats. It is placed under the skin near the heart (figure 4).

●Surgery – Rarely, people with HCM might need surgery to remove part of the heart muscle. This is done only when medicines do not work.

Can I do anything to help my child? — Yes. You can:

●Ask your child's doctor what types of physical activity are safe for your child – Exercising very hard can be dangerous or even life-threatening for children with HCM. But most people with HCM can safely do gentle exercise. Ask the doctor about your child's specific activities.

●Make sure that your child gets all of their vaccines.

●Ask your child's doctor how much water they should drink – People with HCM can have problems, such as fainting, when they do not get enough fluids. But some people with HCM need to be careful if they have too much salt and water. Ask your doctor what is safe for your child, and make sure that they get the right amount.

What will my child's life be like? — Your child will probably need regular exams and tests, medicines, or other treatments. They might also need to avoid certain activities.

A few people with HCM get serious heart problems. But most people are able to live normal lives.

More on this topic

Patient education: ECG and stress test (The Basics)
Patient education: Echocardiogram (The Basics)
Patient education: Hypertrophic cardiomyopathy in adults (The Basics)
Patient education: Syncope (fainting) (The Basics)
Patient education: Implantable cardioverter-defibrillators (The Basics)

Patient education: Hypertrophic cardiomyopathy (Beyond the Basics)
Patient education: Implantable cardioverter-defibrillators (Beyond the Basics)