There are several different types of cardiomyopathy including:

• Arrhythmogenic right ventricular dysplasia (ARVD): The muscle of the heart is replaced by fat tissue over time and leads to dangerous heart rhythms. This form of cardiomyopathy is often hard to diagnose. It is usually first found when the patient has an abnormal rhythm. This is also sometimes referred to as arrhythmogenic right ventricular dysplasia (ARVD).
• Dilated cardiomyopathy (DCM): DCM is the most common form of cardiomyopathy in children. In DCM, the heart becomes enlarged and does not contract or contracts poorly.
• Hypertrophic cardiomyopathy (HCM): With hypertrophic cardiomyopathy, the heart muscle is thickened. Another name for this is idiopathic hypertrophic subaortic stenosis (IHSS). Hypertrophy, or thickening of the heart walls, can make it hard for blood to flow through the heart. Children with hypertrophic cardiomyopathy are also at increased risk for abnormal heart rhythms, or arrhythmias.
• Restrictive cardiomyopathy (RCM): With restrictive cardiomyopathy, the lower chambers (ventricles) become rigid and are not able to relax properly. As a result, blood gets backed up into the upper chambers (atria) and they become enlarged or bigger, while the lower pumping chambers (ventricles) remain normal in size. This is a rare form of cardiomyopathy in children.
• Left Ventricular Non-compaction cardiomyopathy (LVNC): On echocardiogram, the heart muscle appears coarse and marked with fingerlike projections called trabeculations. It appears coarse and jagged instead of smooth and compact. LVNC may be related to other forms of congenital heart disease, but can occur on its own.

The types and severity of cardiomyopathy symptoms vary from child to child.

Common symptoms in infants may include:

• Lethargy (tiredness) or inactivity
• Poor weight gain
• Fast and heavy breathing with feedings
• Feedings that take longer than normal
• Sweating with feedings
• Trouble breathing

Common symptoms in children or adolescents may include:

• Stomach pain
• Nausea
• Vomiting
• Trouble with exercise
• Changes in their endurance during exercise or not able to keep up with other children their age
• Trouble breathing
• Cough
• Abnormal heartbeats
• Heart palpitations
• Dizziness or fainting
• Decreased appetite

The cause of cardiomyopathy in most cases is idiopathic, or unknown. In other cases, cardiomyopathy may be inherited due to a genetic change or mutation.

Other causes of cardiomyopathy include:

• A viral infection of the heart, called myocarditis, which weakens the heart muscle
• Metabolic disorders
• Inherited muscle disorders, such as Duchenne Muscular Dystrophy or Friedreich's ataxia
• Problems of the coronary arteries, either present at birth or acquired
• Chemotherapy

In addition to the causes listed above, there are other less common forms of cardiomyopathy that can be caused by hormone deficiencies, chronic medical conditions, and rhythm problems.

Physical Exam:

For all patients thought to have cardiomyopathy, the history and physical examination are key in making the diagnosis. Signs of congestive heart failure, such as fast breathing and fast heart rate, abnormal lung and heart sounds, and an enlarged liver can help the doctor make the right diagnosis.

Tests to Help with Diagnosing Cardiomyopathy:

An electrocardiogram (EKG) to evaluate the amount of enlargement as well as the rhythm of the heart is often performed during the initial evaluation.

An echocardiogram, or sonogram of the heart, will give a definitive diagnosis as to the type of cardiomyopathy and the degree of dysfunction of the heart muscle.

A chest X-ray is sometimes used to screen for cardiac disease and can show an enlarged heart and extra fluid in the lungs (also referred to as pulmonary edema).

A cardiac catheterization may also be performed, not only to evaluate the pressures within each chamber of the heart, but also to evaluate the coronary arteries as malformations of these arteries can be a cause of cardiomyopathy. Sometimes small pieces of heart muscle are also taken during the cardiac catheterization for laboratory study. Such heart muscle biopsies are helpful in the evaluation of possible infections of the heart, as well as certain metabolic abnormalities of the heart.

Cardiac magnetic resonance, or an MRI of the heart, provides exquisite detail about the structure, function, and composition of the heart. This test can contribute unique information not given by other imaging techniques, and can even be used to perform virtual surgery in the case of implanting support devices.

Genetic Testing:

Cardiomyopathy is sometimes inherited due to a genetic mutation or change. If one person in a family has been diagnosed with cardiomyopathy, genetic testing may be recommended. You can read more about genetic testing options on the Genetic Testing and Screening page.