Cardiomyopathy is a chronic disease in which the heart muscle (myocardium) becomes abnormally enlarged, thickened, and/or stiffened. As a result, the heart cannot contract or relax normally, and its ability to pump blood is insufficient to keep up with the needs of the body. In advanced stages of the disease, irregular heartbeats (arrhythmia) and heart failure may occur.

Cardiomyopathy is a term used to classify different subtypes of the disease that affects the heart muscle. Cardiomyopathy is classified in the following ways:

  • Primary or secondary
  • Ischemic or non-ischemic
  • By subtype

Primary or Secondary Cardiomyopathy

Primary cardiomyopathy refers to cases in which the disease is isolated to the heart and occurs by itself. When it manifests for unknown reasons, it is called idiopathic cardiomyopathy.

Secondary cardiomyopathy refers to cases in which the heart is affected because of another related cause. This could be related to an inflammation of the heart muscle (myocarditis) caused by a virus, exposure to certain toxins or chemotherapy drugs, or a side effect from a systemic disorder that affects multiple organs. These system-wide disorders include muscular dystrophies, lysosomal storage diseases, metabolic disorders, and autoimmune diseases.

Ischemic or Non-Ischemic Cardiomyopathy

Ischemic cardiomyopathy is caused by lack of blood supply to the heart because of coronary artery disease (hardening of the arteries). Ischemic cardiomyopathy most often occurs in adults. Non-ischemic cardiomyopathy results from the abnormal structure and function of the heart itself. Cardiomyopathies affecting children are classified as non-ischemic.

Types of Non-Ischemic Cardiomyopathy

Cardiomyopathy is divided into five types based on the specific damage to the heart muscle. Some patients may be diagnosed with more than one type of cardiomyopathy and the diagnosis may change over time. This is called an undulating phenotype.

Dilated and hypertrophic cardiomyopathy are the most common forms. Restrictive, arrhythmogenic, and left ventricular noncompaction cardiomyopathy occur less frequently in children.

Additional Resources

The Children’s Cardiomyopathy Foundation provides a wide range of materials to help families better understand the disease. Visit our Educational Materials page to download information on the various forms of cardiomyopathy.

Understanding Pediatric Cardiomyopathy

Pediatric Cardiomyopathy FAQ

Secrets of the Heart – Living with Pediatric Cardiomyopathy