Dilated Cardiomyopathy (DCM), also known as congestive cardiomyopathy, is the most common form of cardiomyopathy in children. About 50 to 60 percent of all pediatric cardiomyopathy cases are diagnosed as DCM, or approximately six out of every million children each year. DCM is reportedly more common in boys than girls. Although all age groups are affected, studies show that DCM is more common in infants (before age 1 year) than in children.
DCM occurs when the muscles in one of more of the heart’s chambers become enlarged or stretched (dilated). The other chambers of the heart must work harder to compensate for the affected chambers, and they too also may become dilated and enlarged. As the condition progresses, the heart becomes weaker, unable to pump blood through the body. This can lead to congestive heart failure and cause a build-up of fluid in the lungs, liver, abdomen and lower legs.
Causes of Dilated Cardiomyopathy
In a large majority of cases, the exact cause of DCM cannot be determined (idiopathic cardiomyopathy). In children, DCM is often acquired by a viral infection that causes inflammation of the heart muscle (myocarditis) and permanently damages the heart muscle cells. Exposure to cancer-treatment drugs (anthracycline cardiotoxicity) is also a common cause of DCM in children. In addition, children with congenital heart disease may develop DCM from multiple attempts to repair the heart.
DCM can be inherited; an estimated 20 to 30 percent of people with DCM have a parent or sibling with the disease. Children may also develop DCM in association with genetic disorders of a metabolic, neuromuscular, endocrine or hematologic basis.