Dilated Cardiomyopathy

Alternate Names
dilated congestive cardiomyopathy

Definition of Dilated Cardiomyopathy

The heart is made up of muscle, valves, supporting structures, an electrical conduction system and blood vessels. A cardiomyopathy is any disease of the heart muscle. This term is generally used only when the disease is inside the heart itself, and not due to high blood pressure, clogging of the arteries from atherosclerosis or heart valve problems. In dilated cardiomyopathy, one of the subtypes of this disease, the heart muscle becomes thin and flabby, and the heart becomes enlarged.

What is going on in the body?

This condition makes the heart unable to pump blood effectively. The thin, flabby heart muscle is weak and cannot function properly. This results in a variety of symptoms.

What are the signs and symptoms of the condition?

This is often a disorder that develops slowly over time. An affected person may notice:

• shortness of breath, especially when laying flat or exercising
• chest pain
• fatigue
• lung congestion, known as pulmonary edema
• swelling in the legs, known as edema

A physical exam may reveal:

• low blood pressure
• liver enlargement
• abnormal collections of fluid inside the abdomen, called ascites
• abnormal heart sounds, called heart murmurs
• an abnormally fast heart rate
• sounds of fluid in the lungs
• enlarged neck veins
• swelling of the legs from fluid buildup

What are the causes and risks of the condition?

Sometimes the condition is inherited, but in many cases the cause is unknown. Other possible causes include:

• infections of the heart muscle, such as myocarditis from a viral infection
• alcohol dependence or cocaine abuse
• certain chemotherapy medications used to treat cancer, such as doxorubicin(i.e., Adriamycin) and cyclophosphamide (i.e., Cytoxan)
• exposure to certain chemicals or toxins, such as mercury, lead, and cobalt
• diseases affecting the thyroid gland, such as hypothyroidism, or low thyroid hormone levels in the body
• an abnormally high secretion of growth hormone in children with acromegaly
• low levels of phosphate and calcium in the body
• AIDS, due to HIV infection
• deficiency of thiamine, also known as vitamin B1
• autoimmune disorders, such as rheumatoid arthritis, which occur when a person's immune system attacks his or her own body

What can be done to prevent the condition?

In many cases, this disease cannot be prevented. Avoiding alcohol, cocaine, and other toxic agents can prevent some cases.

How is the condition diagnosed?

A healthcare provider may suspect this disease from the health history and physical exam. A heart tracing (ECG) and chest x-ray may show characteristic changes.

Echocardiography, a test that uses sound waves to look at the heart, can show the flabby heart muscle and how poorly it pumps blood. Other special x-ray tests may also be used in some cases.

Rarely, a biopsy of the heart muscle is advised. This is a procedure to remove a small piece of heart muscle so that it can be analyzed in a lab.

What are the long-term effects of the condition?

This is a very serious condition with a relatively high risk of death. Unless there is a treatable cause, little can be done to prolong life. Death usually occurs from heart failure, irregular heartbeats, or blood clots that develop in the heart.

What are the risks to others?

There are no risks to others.

What are the treatments for the condition?

Those with exposure to toxic substances, such as cocaine or alcohol, need to stop the exposure right away. Those with treatable causes, such as hypothyroidism, need treatment for the cause. In these cases, treatment may help the heart get back much of its normal function.

In cases without a treatable cause, heart medications are used to help the heart pump more effectively. Other heart medications help prevent irregular heartbeats, called arrhythmias. Diuretics (water pills), and reducing salt in the diet can help prevent fluid buildup in the body.

Affected people need plenty of rest and stress reduction. Exercise is encouraged if the person is able. Severely affected people may need a heart transplant.

What are the side effects of the treatments?

Every type of medication has its own set of side effects. For instance, diuretics can cause dehydration and salt imbalances. A heart transplant is a high risk surgery that may result in bleeding, infection, or death.

What happens after treatment for the condition?

The condition often becomes more severe with time even with the best treatment, and is often fatal. Newer heart medications may slow the progression of the condition. After a heart transplant, people need close monitoring and must take powerful medications to prevent rejection of the new heart. If successful, a transplant will prolong life.

How is the condition monitored?

The medications used to help strengthen the heart need to be monitored and often adjusted. After a heart transplant, a person is watched closely to see if his or her body will reject the new heart.