Cardiomyopathy

Cardiomyopathies are more common in children than previously thought. Furthermore, children may not show cardiomyopathy on testing, but may have high risk of developing it based on their family history and genetic predisposition. The most common cardiomyopathies in children are dilated (enlarged and weaken hearts) or hypertrophic (thick and stiff hearts).

Symptoms of Cardiomyopathies

Symptoms vary based on the type of cardiomyopathy. For those with either dilated or hypertrophic cardiomyopathy, the signs are similar to congestive heart failure.

In babies, symptoms may include:

• Breathing problems during feeding
• Lack of energy
• Longer than normal feedings
• Poor weight gain

In older children and teens, common symptoms are:

• Abdominal pain
• Abnormal heartbeat sensations (palpitations)
• Breathing problems
• Coughing
• Dizziness
• Lack of appetite
• Nausea
• Passing out and inability to exercise for extended periods of time
• Vomiting

Sometimes cardiomyopathy has no symptoms, especially in its earliest stages. The condition may be discovered during tests for another health issue or a sports physical. These patients often benefit from medications and regular visits with a cardiologist who specializes in congenital heart defects.

If cardiomyopathy is secondary and caused by an infection, patients may notice fever, chills and achiness before heart-related symptoms appear.

Diagnosis of Cardiomyopathy

If your doctor suspects your child has a form of cardiomyopathy, diagnosis begins with a health history, a physical examination and possibly blood test. Other tests may include:

• Electrocardiogram (EKG): This simple, painless test is often the first test. It is designed to record the heart’s electrical activity through electrodes attached to the skin like bandages.
• Echocardiography (Echo): This painless ultrasound uses sound waves to create pictures that show the size, shape and function of the heart. Doctors use echo to see the type and severity of the cardiomyopathy.
• Cardiac MRI. Occasionally, an MRI of the heart is needed to get more detail about the heart. Cardiac MRIs are also used to get more information when a patient’s echocardiograms are inconclusive. This test provides information about the structure and function of the heart. Dye may be injected to provide additional information. This test may be done under general anesthesia in young children and without anesthesia in older children.
• Chest X-ray. X-rays can provide yet another set of images, primarily to show whether the heart is enlarged or if the lungs have extra fluid (a sign of heart failure).
• Holter and Event Monitors. Patients wear these small portable devices, which record the heart’s electrical activity during normal daily activities. These are like “take home EKGs” that collect data for 24 to 48 hours.
• Stress Test. A series of tests may be performed while your child’s heart is working hard and beating fast. Usually done in school-age children or older, it involves walking/running on a treadmill or riding an exercise bike while blood pressure, EKG and breathing are monitored. Your child will exercise (or be given medicine) to increase heart rate and activity.
• Genetic Testing. Genetic blood tests may be ordered when a doctor suspects cardiomyopathy, but your child is not showing symptoms. Since some heart issues run in families, your child’s doctor may recommend tests for parents and siblings. 
• Cardiac Catheterization. This procedure is typically done under general anesthesia, except in teenagers and adults where local anesthetic may be all that is necessary. A small, flexible tube is threaded through a vein in the arm, upper thigh or neck. As a diagnostic step, special dye is injected, allowing the doctor to see how the blood flows through the heart and blood vessels. Pressure inside the heart can also be measured. Sometimes, tiny pieces of heart muscle are also taken for further study (heart biopsy).