Cardiomyopathy in Children & Teens

What Is Cardiomyopathy?

Cardiomyopathy is a disease of the heart muscle. It is a chronic condition where the muscle becomes abnormally enlarged, thickened or stiff with deterioration of heart muscle function over time eventually making it difficult for the heart to pump blood to the rest of the body. There are various types of cardiomyopathy and reasons a child may develop this condition. The abnormal heart muscle can be caused by genetic mutations or acquired conditions throughout the lifespan. It can be difficult to determine how long the cardiomyopathy has been present as children may be asymptomatic for a period of time prior to developing symptoms of heart failure.  

What Are the Types of Cardiomyopathy?

A few common types of cardiomyopathy in pediatrics are described below.

Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy is characterized by abnormal thickening (hypertrophy) of the heart muscle. The muscle can be thickened in such a way that it obstructs blood flow out of the heart (hypertrophic obstructive cardiomyopathy or HOCM). In many cases of hypertrophic cardiomyopathy, there is a genetic cause, so family members of those diagnosed should also be screened. Those with HCM can suffer from sudden, life-threatening rhythm abnormalities that may be associated with strenuous exercise. Therefore, people with this type of cardiomyopathy are often restricted from competitive sports or strenuous activity. There is no definitive cure for hypertrophic cardiomyopathy, though surgeries or other procedures are sometimes performed to remove muscle that is causing obstruction. Heart transplantation may be required if symptoms cannot be controlled with medications or other surgical interventions.

Restrictive Cardiomyopathy

Restrictive cardiomyopathy is characterized by a stiffened heart muscle that cannot relax normally between heartbeats. This impairs the ability of blood to fill the ventricles (lower chambers of the heart) and get pumped out to the rest of the body. When blood cannot easily drain into the ventricles it may back up into the top chambers of the heart causing them to enlarge increasing the risk of rhythm abnormalities and clot formation. Furthermore, blood can back up into other places in the body such as the lungs and liver, causing swelling and other symptoms. Medical treatments for restrictive cardiomyopathy are aimed to control symptoms, and heart transplantation is frequently required for those with a severe form of the disease.  

Dilated Cardiomyopathy

Dilated cardiomyopathy is the most common type of cardiomyopathy in children. It is characterized by an enlarged and weakened heart muscle. It often starts with the lower left chamber of the heart and in severe cases other chambers of the heart might become affected as well. The enlarged muscle chamber loses the ability to contract (or squeeze) effectively and pump blood to the rest of the body. Depending on severity of the disease, some children may have no symptoms while others develop symptoms of heart failure such as difficulty breathing, gastrointestinal symptoms, poor growth, etc. There are several medications that are effective in improving heart muscle function and symptoms in patients with dilated cardiomyopathy. Those who continue to have symptoms of heart failure despite treatment with medications may be considered for heart transplant.

What Are the Causes of Cardiomyopathy?

Cardiomyopathies may be present at birth, also known as congenital cardiomyopathy, or develop later in life. Cardiomyopathies can be inherited and passed down in families due to genetic variations. Other times, cardiomyopathies develop because of another medical condition such as infections (bacterial or viral), autoimmune or inflammatory conditions, toxin exposure (such as chemotherapy), metabolic diseases, neuromuscular disorders, endocrine abnormalities, nutritional deficiencies, and more. In many cases however, the cause of the cardiomyopathy is not identifiable. Since cardiomyopathy is often genetic, it is important to consider family screening for anyone newly diagnosed.

What Are the Symptoms of Cardiomyopathy?

Symptom type and severity vary widely in children and teens with cardiomyopathy. Some children may have no symptoms at all despite their abnormal heart muscle, while others may present with typical symptoms of heart failure. Symptoms often vary depending on type of cardiomyopathy and the child’s age. Common presenting symptoms by age are included below. 


  • Difficulty feeding 
  • Poor growth 
  • Irritability 
  • Labored or difficulty breathing  

Older Children 

  • Difficulty breathing/Shortness of breath 
  • Chest pain 
  • Unusual fatigue 
  • Dizziness or fainting  
  • Loss of appetite 
  • Vomiting 
  • Heart palpitations  
  • Swelling  

Occasionally symptoms can be mistaken for common childhood illnesses leading to a delayed diagnosis of cardiomyopathy. Unfortunately, the first symptom can also be sudden death due to an abnormal heart rhythm.

What Is the Treatment for Cardiomyopathy?

Treatment depends on the type of cardiomyopathy and severity of symptoms. Children who do not have symptoms may not require treatment and will likely be followed closely by their cardiologist.  
Goals of treatment often include reducing stress on the heart to prevent/delay worsening of heart muscle function over time, and to improve symptoms. Treatment may include medications and in some cases surgery.  


Different medications may be prescribed based on the type of cardiomyopathy and what symptoms are present. There are medications that can help the heart muscle relax, squeeze with more force, get rid of extra fluid in the body and lungs, control the heart rate and rhythm, prevent blood clots from forming, and more.  

Surgical Interventions  

Pacemakers may be surgically implanted to monitor and control the heart rate. Defibrillators may be surgically implanted to detect and control abnormal heart rhythms, most commonly in children with hypertrophic cardiomyopathy who are at increased risk of abnormal rhythms. Myectomy, or removal of part of the heart muscle, may be performed in children with hypertrophic cardiomyopathy if the thickened muscle obstructs blood flow into or out of the heart. Ventricular assist devices may be implanted to help do the work of the ventricles, the lower chambers of the heart, in pumping blood out to either the lungs or the body. These devices may eventually be removed if the heart muscle recovers or used to bridge a child to a heart transplant. Children with severe cardiomyopathy whose symptoms cannot be managed with medications or surgeries described above, may require a heart transplant as treatment for the condition.  

Learn more about our Families with Cardiomyopathy Clinic and Cardiovascular Genetics Clinic

What Are the Long-term Effects of Cardiomyopathy?

Although cardiomyopathy is a chronic illness, many children with this condition can live a relatively normal life with minimal limitations depending on cardiomyopathy type and severity. There is no cure for the illness, but there are medical and surgical therapies available to help improve a child’s symptoms. Heart transplantation is a universal treatment for all types of cardiomyopathies but is only considered for children who do not respond to alternate therapies as heart transplant carries its own set of risks and complications.

With the different treatment options available for cardiomyopathy, the outlook is good, though life expectancy may be shortened. Quality of life will depend on the severity of the disease and can often be improved with heart transplantation if medications are unsuccessful in controlling symptoms. 

Heart Center Family Resource Guide

To help prepare families for their care with Lurie Children's Heart Center, we have compiled a list of resources about treatment and recovery. Learn how to get ready for an inpatient stay or outpatient visit, and read about our support services for patients and families.

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