Dilated cardiomyopathy is a disease of the heart muscle, usually starting in your heart's main pumping chamber (left ventricle). The ventricle stretches and thins (dilates) and can't pump blood as well as a healthy heart can. The term "cardiomyopathy" is a general term that refers to the abnormality of the heart muscle itself.
Dilated cardiomyopathy might not cause symptoms, but for some people it can be life-threatening. A common cause of heart failure — the heart's inability to supply the body with enough blood — dilated cardiomyopathy can also contribute to irregular heartbeats (arrhythmias), blood clots or sudden death.
The condition affects people of all ages, including infants and children, but is most common in men ages 20 to 50.
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If you have dilated cardiomyopathy, you're likely to have signs and symptoms of heart failure or arrhythmias caused by your condition. Signs and symptoms include:
- Shortness of breath (dyspnea) when you're active or lying down
- Reduced ability to exercise
- Swelling (edema) in your legs, ankles and feet
- Swelling of your abdomen due to fluid buildup (ascites)
- Chest pain
- Extra or unusual sounds heard when your heart beats (heart murmurs)
When to see a doctor
If you're short of breath or have other symptoms of dilated cardiomyopathy, see your doctor as soon as possible. Call 911 or your local emergency number if you feel chest pain that lasts more than a few minutes or have severe difficulty breathing.
If a family member has dilated cardiomyopathy, talk to your doctor about being screened or having family members screened for the condition. Early detection using genetic testing may benefit people with inherited forms of dilated cardiomyopathy who have no apparent signs or symptoms.
Compared with a normal heart, dilated cardiomyopathy causes the chambers of the heart to enlarge, which can lead to heart failure if left untreated.
The cause of dilated cardiomyopathy often can't be determined. However, numerous factors can cause the left ventricle to dilate and weaken, including:
- High blood pressure (hypertension)
- Alcohol abuse
- Certain cancer medications
- Cocaine use and abuse
- Infections, including those caused by bacteria, viruses, fungi and parasites
- Exposure to toxins, such as lead, mercury and cobalt
- Complications of late-stage pregnancy
Dilated cardiomyopathy most commonly occurs in men, ages 20 to 50. But it can also occur in women. Other risk factors include:
- Damage to the heart muscle from a heart attack
- Family history of dilated cardiomyopathy
- Inflammation of heart muscle from immune system disorders, such as lupus
- Neuromuscular disorders, such as muscular dystrophy
Complications from dilated cardiomyopathy include:
- Heart failure. Poor blood flow from the left ventricle can lead to heart failure. Your heart might not be able to supply your body with the blood it needs to function properly.
- Heart valve regurgitation. Enlargement of the left ventricle may make it harder for your heart valves to close, causing a backward flow of blood and making your heart pump less effectively.
- Fluid buildup (edema). Fluid can build up in the lungs, abdomen, legs and feet (edema).
- Abnormal heart rhythms (arrhythmias). Changes in your heart's structure and changes in pressure on your heart's chambers can contribute to the development of arrhythmias.
- Sudden cardiac arrest. Dilated cardiomyopathy can cause your heart to suddenly stop beating.
- Blood clots (emboli). Pooling of blood (stasis) in the left ventricle can lead to blood clots, which may enter the bloodstream, cut off the blood supply to vital organs, and cause stroke, heart attack or damage to other organs. Arrhythmias can also cause blood clots.
Healthy lifestyle habits can help you prevent or minimize the effects of dilated cardiomyopathy. If you have dilated cardiomyopathy:
- Don't smoke.
- Don't drink alcohol, or drink in moderation.
- Don't use cocaine or other illegal drugs.
- Eat a healthy diet, especially a low-salt (sodium) diet.
- Maintain a healthy weight.
- Follow an exercise regimen recommended by your doctor.
- Get enough sleep and rest.