Dilated Cardiomyopathy (DCM)

Dilated cardiomyopathy (DCM) is the most common type, occurring mostly in adults younger than 50. It affects the heart's ventricles and atria, the lower and upper chambers of the heart.

Dilated cardiomyopathy is more common in Black people than in white people. It's also more prevalent in men than in women.

Frequently, the disease starts in the left ventricle, the heart's main pumping chamber. The heart muscle begins to dilate, stretching and becoming thinner. As a result, the inside of the chamber enlarges. The problem often spreads to the right ventricle and then to the atria.

As the heart chambers dilate, the heart muscle doesn't contract normally and can't pump blood very well. As the heart becomes weaker, heart failure can occur. Common symptoms of heart failure include shortness of breath, fatigue and swelling of the ankles, feet, legs, abdomen and veins in the neck.

Dilated cardiomyopathy also can lead to heart valve problems, arrhythmias (irregular heartbeats) and blood clots in the heart.

Other names for dilated cardiomyopathy

  • Alcoholic cardiomyopathy. (Overuse of alcohol causes the disease.)
  • Congestive cardiomyopathy
  • Diabetic cardiomyopathy
  • Familial dilated cardiomyopathy
  • Idiopathic cardiomyopathy
  • Ischemic cardiomyopathy (Coronary heart disease, also called coronary artery disease, or heart attack cause the disease. Not all forms of DCM are ischemic in origin.)
  • Peripartum cardiomyopathy (When the disease develops in a woman shortly before or after she gives birth)

What causes dilated cardiomyopathy?

The cause of dilated cardiomyopathy often isn't known.

Some diseases, conditions and substances also can cause the disease, such as:

  • Coronary heart disease, heart attack, high blood pressure, diabetes, thyroid disease, viral hepatitis and HIV
  • Infections, especially viral infections that inflame the heart muscle
  • Alcohol, especially if you also have a poor diet
  • Complications during the last month of pregnancy or within five months of birth
  • Certain toxins such as cobalt
  • Certain drugs (such as cocaine and methamphetamines) and two medicines that treat cancer (doxorubicin and daunorubicin)

Dilated cardiomyopathy in infants and children

Infants and young children with DCM may be misdiagnosed with a viral upper respiratory tract infection or recurrent pneumonia without realizing a heart problem is the underlying cause for their symptoms. Older children and adolescents are more likely to have abdominal pain, decreased exercise capacity or increased fatigue. In many children with DCM, chronic coughing and wheezing during activity may be mistaken for asthma.

Many children with DCM can lead relatively normal lives once a diagnosis has been confirmed and appropriate treatments are started. However, a diagnosis of DCM does affect several areas of a child’s life. Specific recommendations should be developed by the child’s health care team.