What is Dilated Cardiomyopathy?

Dilated cardiomyopathy is the most common type of cardiomyopathy. It is a disease of the heart muscle that causes the four chambers of the heart (atria and ventricles) to enlarge (dilate) and squeeze poorly. The cause is unknown in the majority of cases, but it can also be linked to genetic conditions, infections, certain toxic medications, poor nutrition, abnormal heart rhythms, hormonal effects or physiologic changes such as pregnancy. In adults, DCM can be an effect of ischemia (poor blood supply to the heart muscle such as in cases of obstructed coronary arteries) or high blood pressure.

Effects and Symptoms

DCM can cause heart failure symptoms in infants and children that can present as shortness of breath, a fast heart rate and congestion or fluid build up in the lungs and the liver. Older children can experience fatigue, weakness and poor exercise tolerance.

Diagnosis

Children who do not have symptoms are diagnosed through screening for another genetic or neuromuscular condition or a known close relative (a parent, sibling or child) with cardiomyopathy. Others may present with heart failure symptoms that are either accompanied by a stressor such as an infection or exercise, or a long standing history of poor exercise tolerance. 

Tests that help with diagnosis are: 

• A chest xray may show an enlarged heart with or without fluid congestion in the lungs. 
• An ECG can show signs of enlarged heart chambers or abnormal heart rhythms. 
• An echocardiogram can show dilation of the four chambers and evaluate the heart’s function. 
• A cardiac MRI can provide additional information in the heart’s anatomy that can help with management and monitoring. It can be useful in identifying the cause of DCM in certain cases and distinguish it from other forms of cardiomyopathy as well. 

Testing for a child with DCM is tailored for the individual because there are several causes for DCM. Genetic testing can also be performed in search of a genetic cause.

Management and Treatment

The goal of treatment in children with DCM is to manage symptoms and to look for possible causes of DCM. Laboratory and imaging tests will be performed to investigate for a cause and treatment will be targeted towards this if one is found. Heart failure medications will be started for those with symptoms. Bed rest and activity restrictions are needed in hearts with poor function. A blood thinner is recommended in those at high risk for clot formation to prevent stroke. Abnormal heart rhythms are treated accordingly. 

Family screening may also be recommended in first degree relatives of patients with DCM if a genetic cause is suspected.

Adult and Adolescent Management

Lifelong cardiology follow up is needed for monitoring and continued management.

Women of child-bearing years are counseled about contraceptives and pregnancy. Oral contraceptive pills can increase the risk of blood clot formation and incidence of stroke. Normal changes in pregnancy will cause stress on the heart and is not recommended in those with poor heart function. A consultation and counseling with a cardiologist is necessary for those who have plans of getting pregnant.