Often, the cause of the cardiomyopathy is unknown. In some people, however, doctors are able to identify some contributing factors. Possible causes of cardiomyopathy include:
- Genetic conditions
- Long-term high blood pressure
- Heart tissue damage from a previous heart attack
- Chronic rapid heart rate
- Heart valve problems
- Metabolic disorders, such as obesity, thyroid disease or diabetes
- Nutritional deficiencies of essential vitamins or minerals, such as thiamin (vitamin B-1)
- Pregnancy complications
- Drinking too much alcohol over many years
- Use of cocaine, amphetamines or anabolic steroids
- Use of some chemotherapy drugs and radiation to treat cancer
- Certain infections, which may injure the heart and trigger cardiomyopathy
- Iron buildup in your heart muscle (hemochromatosis)
- A condition that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis)
- A disorder that causes the buildup of abnormal proteins (amyloidosis)
- Connective tissue disorders
Types of cardiomyopathy include:
March 17, 2015
Dilated cardiomyopathy. This is the most common type of cardiomyopathy. In this disorder, the pumping ability of your heart's main pumping chamber — the left ventricle — becomes less forceful. The left ventricle becomes enlarged (dilated) and can't effectively pump blood out of the heart.
Although this type can affect people of all ages, it occurs most often in middle-aged people and is more likely to affect men. Some people with dilated cardiomyopathy have a family history of the condition. In others, dilated cardiomyopathy may occur as a result of certain conditions such as coronary heart disease, infection, chemotherapy, or drug or alcohol use. The cause may also be unknown (idiopathic).
Hypertrophic cardiomyopathy. This type involves abnormal thickening of your heart muscle, particularly affecting the muscle of your heart's main pumping chamber (left ventricle). The thickened heart muscle can make it harder for the heart to pump blood.
Hypertrophic cardiomyopathy can develop at any age, but the condition tends to be more severe if it becomes apparent during childhood. Most affected people have a family history of the disease, and some genetic mutations have been linked to hypertrophic cardiomyopathy.
Restrictive cardiomyopathy. The heart muscle in people with restrictive cardiomyopathy becomes rigid and less elastic, meaning the heart can't properly expand and fill with blood between heartbeats. While restrictive cardiomyopathy can occur at any age, it most often tends to affect older people. It's the least common type of cardiomyopathy and can occur for no known reason (idiopathic).
The condition may also be caused by diseases elsewhere in the body that affect the heart, such as a disease in which iron builds up in the heart muscle (hemochromatosis), a disorder that causes the buildup of abnormal proteins (amyloidosis), a disease that causes inflammation and can cause lumps of cells to grow in the heart and other organs (sarcoidosis), connective tissue disorders, or a disorder that causes abnormal blood cells to damage the heart (eosinophilic heart disease).
- Arrhythmogenic right ventricular dysplasia. In this rare type of cardiomyopathy, the muscle in the lower right heart chamber (right ventricle) is replaced by scar tissue. This can lead to heart rhythm problems. This condition is often caused by genetic mutations.
- Other types of cardiomyopathy. Other types of cardiomyopathy (unclassified cardiomyopathies) exist, but they don't fit within the other types of cardiomyopathy.
- Longo DL, et al. Cardiomyopathy and myocarditis. In: Harrison's Principles of Internal Medicine. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com. Accessed Feb. 2, 2015.
- What is cardiomyopathy? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/cm/printall-index.html. Accessed Feb. 3, 2015.
- Cooper LT. Definition and classification of the cardiomyopathies. http://www.uptodate.com/home. Accessed Feb. 4, 2015.
- Yancy CW, et al. 2013 ACCF/AHA guideline for the management of heart failure: A report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation. 2013;128:e240.
- Gersh BJ, et al. 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy. Journal of the American College of Cardiology. 2011;58:e212.
- Colucci WS. Evaluation of the patient with heart failure or cardiomyopathy. http://www.uptodate.com/home. Accessed Feb. 2, 2015.
- Sisakian H. Cardiomyopathies: Evolution of pathogenesis concepts and potential for new therapies. World Journal of Cardiology. 2014;6:478.
- McKenna WJ. Treatment and prognosis of arrhythmogenic right ventricular cardiomyopathy. http://www.uptodate.com/home. Accessed Feb. 4, 2015.
- Prevention and treatment of cardiomyopathy. American Heart Association. http://www.heart.org/HEARTORG/Conditions/More/Cardiomyopathy/Prevention-and-Treatment-of-Cardiomyopathy_UCM_444176_Article.jsp. Accessed Feb. 5, 2015.
- Why arrhythmia matters. American Heart Association. http://www.heart.org/HEARTORG/Conditions/Arrhythmia/WhyArrhythmiaMatters/Why-Arrhythmia-Matters_UCM_002023_Article.jsp. Accessed Feb. 5, 2015.
- How are arrhythmias treated? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/arr/treatment. Accessed Feb. 5, 2015.
- Mankad R (expert opinion). Mayo Clinic, Rochester, Minn. March 4, 2015.
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