DefinitionCardiomyopathy is a heart disease. The damaged heart does not pump blood correctly. The disease usually progresses, and patients develop life-threatening heart failure . People with cardiomyopathy are also more likely to have irregular heartbeats or arrhythmias . There are two categories of cardiomyopathy: ischemic and non-ischemic. Ischemic cardiomyopathy is most common. It occurs when the heart is damaged from heart attacks due to coronary artery disease . Non-ischemic cardiomyopathy is less common. It includes types of cardiomyopathy that are not related to coronary artery disease. There are three main types of non-ischemic cardiomyopathy:
- Dilated—Damaged heart muscles lead to an enlarged, floppy heart. The heart stretches as it tries to make up for a weakened ability to pump.
- Hypertrophic—Heart muscle fibers enlarge abnormally. The heart does not relax correctly between beats. The heart wall thickens, leaving less space for blood to fill the chambers, so less blood is pumped from the heart.
- Restrictive—Parts of the heart wall stiffen. Thickening often occurs due to abnormal tissue invading the heart.
|Normal Heart and Heart With Hypertrophic Cardiomyopathy|
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CausesIn many cases, the exact cause is not known. Possible causes include:
DilatedThe cause of the initial damage is often not found, but may include:
- Ischemic heart disease with decreased blood flow to your heart
- Infections, usually viral
- Chronic exposure to toxins, including alcohol and some chemotherapy drugs
- A rare complication of pregnancy or childbirth (probably immune-related)
- Rarely, other illnesses, including rheumatoid arthritis , diabetes, or thyroid disease
HypertrophicCauses may include:
- Inherited—sometimes present at birth but often developing in teens
- Aging, associated with hypertension
RestrictiveCauses are usually related to another condition, such as:
- Amyloidosis —Protein fibers collect in the heart
- Sarcoidosis —Small inflammatory masses (granulomas) form in many organs
- Hemochromatosis —Too much iron in the body
Risk FactorsFactors that increase your chance of getting cardiomyopathy include:
- Family members with cardiomyopathy
- Coronary artery disease
- Certain drugs
SymptomsSymptoms vary, depending on the type of cardiomyopathy and its severity.Cardiomyopathy leads to heart failure and the following symptoms:
- Shortness of breath, often worse when lying down or with activity
- Swelling in feet or legs
- Chest pain
- Irregular heart rhythm
DiagnosisYou will be asked about your symptoms and medical history. A physical exam will be done. A stethoscope will be used to listen to your heart. Cardiomyopathies often produce heart murmurs and other abnormal sounds. Images of your chest may be needed. This can be done with:
- Blood tests
- Heart biopsy
TreatmentHeart failure may be due to blockages in the arteries. Treatments to relieve these blockages include angioplasty , stent placement , and coronary artery bypass surgery . These may lead to improved heart function and symptoms. For certain genetic causes, other treatments may also improve heart function. For many patients, however, treatment is aimed at relieving symptoms and preventing further damage.
Lifestyle ModificationChanges to eliminate anything that adds to the disease or worsens symptoms:
- Avoid alcohol.
- If you are overweight, talk to your doctor about ways to help you lose weight .
- Eat a low-fat diet to reduce the risk and extent of coronary artery disease.
- Limit salt intake to reduce fluid retention.
- Follow your doctor's advice about exercise . You may need to limit physical activity.
MedicationsMedications may include:
- Diuretics—To remove extra fluid
- Angiotensin-converting enzyme (ACE) inhibitors—To relax blood vessels, lower blood pressure, and decrease the heart's workload
- Angiotensin receptor blockers—Similar to ACE inhibitors
- Hydralazine and isosorbide dinitrate—May be used with ACE inhibitors
- Digitalis—To slow and regulate heart rate, and slightly increase its force of contractions
- Beta-blockers—To slow the heart and limit disease progression
- Spironolactone—To improve the outcome in people with dilated cardiomyopathy and advanced symptoms
SurgerySurgical options include:
- A pacemaker may be implanted to improve heart rate and pattern.
- For people with hypertrophic disease, doctors may remove part of the thickened wall that separates the heart's chambers. Surgery may be needed to replace a heart valve. Another option is alcohol septal ablation. This procedure reduces symptoms and improves how the heart functions.
- For those with life-threatening, irregular heart rhythms, a cardioverter defibrillator may need to be implanted.
- A heart transplant may be possible for otherwise healthy patients who do not respond to medical treatment. Candidates often wait a long time for a new heart. Those waiting may temporarily receive a ventricular assist device. This is a mechanical pump that takes over some or most of the heart's pumping function.
PreventionActively treat hypertension, coronary artery diseases, and their risk factors. This is the best way to prevent most cases of cardiomyopathy. However, other less common causes are not preventable. If you have a family history of the disease, ask your doctor about screening tests. Do this especially before starting an intense exercise program.
American Heart Association
Heart Rhythm Society
Canadian Cardiovascular Society
The College of Family Physicians of Canada
Dilated cardiomyopathy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated April 2, 2014. Accessed September 9, 2014.
Echt DS, Packer D, et al. Multicenter unsustained tachycardia trial. N Engl J Med. 1999;341:1882-1890.
Heart Failure Society of America 2010 executive summary of heart failure practice guidelines. J Card Fail. 2010;16:475-539.
Peripartum cardiomyopathy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed . Updated July 18, 2014. Accessed September 9, 2014.
Restrictive cardiomyopathy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed . Updated June 12, 2013. Accessed September 9, 2014.
What is cardiomyopathy? National Heart Lung and Blood Institute website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/cm. Updated January 1, 2011. Accessed September 9, 2014.
- Reviewer: Michael J. Fucci, DO
- Review Date: 08/2014
- Update Date: 09/09/2014
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