Dilated Cardiomyopathy (DCM) in Children

Dilated cardiomyopathy (DCM) is a disease of the heart muscle. In DCM, the bottom chamber (left ventricle) of the heart becomes enlarged (dilated), thinning the ventricle walls and reducing the heart's ability to squeeze effectively and pump blood efficiently.

Dilated cardiomyopathy (DCM) is a disease of the heart muscle. In DCM, the bottom chamber (left ventricle) of the heart becomes enlarged (dilated), thinning the ventricle walls and reducing the heart's ability to squeeze effectively and pump blood efficiently.

In many cases, DCM occurs without reason. When your child's doctor can determine the cause, the most common reasons include:

  • a viral infection of the heart causing muscle inflammation (myocarditis), which weakens the heart muscle
  • a genetic condition
  • a metabolic disorder
  • a problem with the coronary arteries, which can be present at birth or acquired

Symptoms & Signs

DCM typically presents with signs and symptoms of congestive heart failure.

Infants may have:

  • fast breathing and sweating during feedings
  • feedings that take longer than normal
  • lethargy or inactivity
  • poor weight gain

Children and Adolescents may have:

  • shortness of breath (initially triggered by exercise, but over time may also occur at rest)
  • shortness of breath when lying flat
  • fatigue
  • persistent cough
  • swelling in face, abdomen, legs, or feet 
  • unexplained weight gain
  • dizziness or lightheadedness
  • fainting or passing out (syncope)
  • abnormal heartbeats
  • nausea and vomiting
  • decreased appetite


Your child's doctor may use medical and family histories, physical exams, and cardiac testing to confirm a DCM diagnosis. Examples of cardiac testing include:

  • An ECG/EKG to evaluate the amount of enlargement as well as the rhythm of the heart
  • An echocardiogram to help measure the dilation of the ventricles and the overall squeeze of the heart
  • A chest X-ray to reveal 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
  • Cardiac catheterization to evaluate pressure in each chamber of the heart and examine the coronary arteries. Sometimes, a biopsy is needed to assist with the diagnosis. These heart muscle biopsies help identify possible infections or specific metabolic abnormalities of the heart


Clinical management of DCM depends on the severity of the disease and the patient's symptoms. Your child's doctor may prescribe medications to help improve heart function and minimize symptoms and complications. Such medications are used to:

  • dilate blood vessels allowing the heart to pump easier (angiotensin-converting enzyme (ACE) inhibitors)
  • slow the heart rate down and protect against abnormal heart rhythms (beta-blockers and other antiarrhythmic medications)
  • help the body get rid of extra fluid that can build up if the heart is not squeezing well (diuretics)
  • help strengthen the squeeze of the heart and reduce symptoms of heart failure (digoxin)
  • prevent blood clots that can result from poor heart function (blood thinner)
  • prevent the development of scar tissue in the heart muscle (aldosterone antagonist)

When these medications no longer work, advanced heart failure therapies may be considered in certain patients, such as:

  • intravenous medications
  • implantation of an implantable cardioverter defibrillator (ICD) for certain patients deemed at risk for life-threatening arrhythmias
  • implantation of a cardiac resynchronization or biventricular pacemaker in order to restore the normal timing pattern of the heartbeat. This type of pacemaker aims to improve the coordination of the squeeze of the heart muscle and the function of the heart.
  • implantation of a ventricular assist device (VAD) to support the heart while waiting for heart transplantation. This is a pump attached to the heart that helps the heart pump and increases blood flow to the body.
  • heart transplantation if the condition is severe

Lifestyle Changes

Some children with DCM may be restricted from certain sports and activities. "Intense" physical activity may be a risk for children with weakened heart muscles.

Children with DCM should never "push through" a symptom if they feel tired, dizzy, or have difficulty breathing during any 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 focus on what can be done and how to stay safe when participating in activities. Children with DCM should also follow a healthy, well-balanced diet.

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