What Causes Cardiomyopathy?

Many times, the cause of cardiomyopathy is unknown. When this happens, the disease is called idiopathic (or primary) cardiomyopathy. The majority of cardiomyopathies in children are idiopathic.

Sometimes, cardiomyopathy is inherited (passed down in the genes from parent to child) or caused by another disease or condition.

Dilated Cardiomyopathy

Dilated cardiomyopathy can be inherited. It also can be caused by certain diseases, conditions, and substances, including:

• Coronary artery disease and heart attacks (ischemic cardiomyopathy)
• Infections, especially viral infections that cause the heart muscle to become inflamed (myocarditis)
• Alcohol, especially when a person has a poor diet (alcoholic cardiomyopathy)
• Complications during the last month of pregnancy or within 5 months of birth (peripartum cardiomyopathy)
• Certain toxins, such as cobalt
• Certain drugs, such as cocaine, amphetamines, and two medicines used to treat cancer (doxorubicin and daunorubicin)
• Diseases such as diabetes and thyroid disease

Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy can be inherited. It also can develop over time because of high blood pressure or aging. Often, the cause of hypertrophic cardiomyopathy is unknown.

Restrictive Cardiomyopathy

Certain diseases and conditions can cause restrictive cardiomyopathy, including:

• Hemochromatosis, a condition in which too much iron is deposited into tissues, including heart tissue
• Amyloidosis, a disease in which abnormal proteins are deposited into heart tissue
• Sarcoidosis, a disease in which inflammation produces tiny lumps of cells in various organs in the body, including the heart
• Connective tissue disorders

Arrhythmogenic Right Ventricular Dysplasia

Arrythmogenic right ventricular dysplasia is thought to be an inherited disease.