Restrictive Cardiomyopathy in Children
Restrictive cardiomyopathy (RCM) is a rare disease where the heart muscle becomes rigid or stiff. This makes it difficult for the ventricles to relax and properly fill with blood.
RCM can be inherited, and many children have no identifiable reason for their disease.
When the cause can be identified, it may include:
- buildup of abnormal proteins (amyloidosis) in the heart muscle
- excess iron (hemochromatosis) in the heart
- other systemic diseases (sarcoidosis, scleroderma)
- chemotherapy or radiation treatments for certain cancers
- inherited diseases (such as Fabry disease)
Symptoms & Signs
Restrictive Cardiomyopathy (RCM) is a rare disease where the heart muscle becomes rigid or stiff. This makes it difficult for the ventricles to relax and a properly fill with blood.
RCM can be inherited, and many children have no identifiable reason for their disease.
When the cause can be identified, it may include:
- buildup of abnormal proteins (amyloidosis) in the heart muscle
- excess iron (hemochromatosis) in the heart
- other systemic diseases (sarcoidosis, scleroderma)
- chemotherapy or radiation treatments for certain cancers
- inherited diseases (such as Fabry disease)
Diagnosis
Diagnosis of RCM is based on the medical and family history, physical exam, and cardiac testing.
Cardiac Testing:
- An ECG to evaluate the rhythm of the heart and possible enlargement
- An echocardiogram will help measure the enlargement of the upper chambers of the heart (atria). The atria become enlarged because of the increasing pressure from the abnormal relaxation of the ventricles
- A chest X-ray can show an enlarged heart and extra fluid in the lungs
- An exercise stress test to see how the heart reacts to exercise or stress
- A stress echocardiogram, which uses ultrasound and heart-rate monitoring to assess heart function before and after exercise
- A Holter monitor to screen for abnormal heart rhythms
- A cardiac catheterization may be performed to evaluate pressures in each chamber of the heart and look at the coronary arteries. Sometimes some pieces of heart muscle are taken during the procedure. These heart muscle biopsies are helpful in diagnosis of certain causes of RCM.
- Genetic testing to look for genes associated with RCM
- Cardiac MRI may be done. It is a test that uses a magnetic field to obtain very clear pictures of the heart muscle.
- Blood tests such as BNP (B-type natriurectic peptide) which is a blood test that helps show it heart failure is present
Treatment
- The treatment for RCM is focused on minimizing or preventing symptoms, protecting children from abnormal heart rhythms and delaying disease progression.
- Medications are used to treat heart failure symptoms but currently there are not any medications that improve the heart's ability to relax.
- If a child is identified to be at increased risk for sudden cardiac arrest, preventative treatments using medications to control the heart rate (antiarrhythmic medications) or an implantable cardioverter defibrillator (ICD) may be recommended.
- If the condition is severe, a heart transplant may be considered.
Lifestyle Changes
Some children with RCM may be restricted from certain sports and activities. "Intense" physical activity may be a risk for a child with a weakened heart muscle. Children with RCM should never "push through" a symptom if they are feeling tired, dizzy, or have difficulty breathing with an activity. They should remain well hydrated at all times and rest when needed.
It will be important to discuss the sports and activities that are safe and appropriate for your child and to focus on what CAN be done and how to stay safe when participating in activities. Children with RCM should also follow a healthy, well balanced diet.