What is dilated cardiomyopathy?

Dilated cardiomyopathy, or DCM, is when the heart chambers enlarge and lose their ability to contract. It often starts in the left ventricle (bottom chamber). As the disease gets worse, it may spread to the right ventricle and to the atria (top chambers). As the heart chamber widens, it becomes weak and does not contract well. Eventually, the heart can't pump as much blood forward as it normally would. This causes fluid to back up in the lungs and build up in the body. This is called heart failure.

DCM is somewhat uncommon, but not rare. It affects men more often than women and tends to occur in adults ages 20 to 60 years old.

Some types of DCM are reversible. Symptoms may improve with treatment. Other types of DCM are irreversible, and the damage is permanent.

What causes dilated cardiomyopathy?

Many different causes can lead to DCM, such as:

• Infections, such as HIV and Lyme disease
• Autoimmune disease, such as polymyositis
• Alcohol abuse, cocaine use, exposure to heavy metals, and certain chemotherapy drugs
• Thyroid disease
• Diabetes
• High blood pressure
• Irregular heart rhythms
• Response to heart attack or blocked heart arteries (coronary artery disease)
• Heart valve problems
• Nutritional or electrolyte problems (rare in the United States)
• Pregnancy (develops shortly before or after birth)
• Genetic conditions, such as muscular dystrophies

DCM sometimes has different names. For example, alcoholic cardiomyopathy is another name for DCM that occurs from alcohol abuse.

A range of genetic diseases can also cause DCM. These people have what is called familial dilated cardiomyopathy.

For many people with DCM, the cause is unknown. This is called idiopathic dilated cardiomyopathy.

Who is at risk for dilated cardiomyopathy?

If you have a relative with DCM, you may be at higher risk of getting it yourself. If so, you may require monitoring for the disease. Some things you can do to lower your risk include:

• Avoid excess alcohol use
• Treat high blood pressure
• Live a healthy lifestyle and maintaining a healthy weight
• Avoid illegal drug use
• Get prompt treatment for potential causes, like thyroid disease
• Reduce your risk factors for coronary artery disease
• Reduce exposure to heavy metals and other toxic causes

What are the symptoms of dilated cardiomyopathy?

In its early stages, DCM may not have any symptoms. Symptoms may get worse gradually or more quickly. Some symptoms include:

• Shortness of breath with exertion (may progress to shortness of breath when at rest)
• Shortness of breath when lying flat
• Sudden shortness of breath that wakes you up at night
• Fatigue
• Reduced ability to be active and exercise
• Swelling in the legs and other areas
• Fainting
• Weakness or lightheadedness
• Cough
• Abnormal heart rhythms

How is dilated cardiomyopathy diagnosed?

Your healthcare provider will ask you about your medical history. This includes any family history of heart disease or sudden death. He or she will give you a physical exam. You may also have tests such as:

• Echocardiogram, to examine blood flow in the heart and heart motion using ultrasound
• Electrocardiogram (ECG) to analyze the heart rhythm
• Continuous portable ECG monitoring to further analyze heart rhythms away from the healthcare provider’s office
• Chest X-ray to see the heart anatomy
• Exercise testing to see how your heart performs during exercise

Depending on your medical history, you may have other tests such as:

• Cardiac stress testing to look for blood flow problems to the heart
• Blood work to check for various abnormalities or infections, like HIV or Lyme disease
• Blood work to check for autoimmune diseases
• Cardiac MRI to further check the heart anatomy and coronary arteries
• Heart biopsy to look at the heart in more detail
• Cardiac catheterization with coronary angiography to look at the arteries
• Genetic testing

How is dilated cardiomyopathy treated?

Treatment of DCM depends on severity and cause. The first step is to treat any underlying causes. For example:

• Eliminate exposures to toxins, like alcohol and cocaine
• Treat diabetes or thyroid disease
• Treat infectious conditions
• Correct nutritional causes

In some cases, DCM gets much better after treatment of an underlying cause. In other cases, the damage is permanent. Then the treatment focuses on managing symptoms. Your healthcare provider might prescribe treatments such as:

• Diuretics (water pills) to reduce swelling
• Medicines such as beta-blockers to reduce the heart’s workload and make it more efficient
• Medicines, like ACE inhibitors to optimize the pumping function of the heart, protect the heart, and slow the progression of the disease
• Anticoagulants (blood thinners) to prevent blood clots
• Medicines to help prevent abnormal heart rhythms
• Lifestyle changes such as monitoring your fluid and salt intake, eating a heart healthy diet, and exercising

Your healthcare provider might also advise an implantable cardioverter-defibrillator (ICD). You may need this if you are at risk for heart rhythms that can cause sudden death. If you also have coronary artery disease or severe valve disease, you may need a procedure or heart surgery. If your condition becomes very severe, you may need a heart transplant in the future.

What are the complications of dilated cardiomyopathy?

Complications that can occur include:

• Fluid retention
• Stroke (from a blood clot in the heart that travels to the brain)
• Abnormal heart rhythms
• Increased risk of complications during pregnancy
• Heart valve problems
• Sudden cardiac death from a dangerous heart rhythm

Can dilated cardiomyopathy be prevented?

Some cases of DCM can be prevented. Avoiding abuse of alcohol and illegal drugs may prevent DCM. Quick treatment of other medical causes can also prevent some cases of DCM.

How do I manage dilated cardiomyopathy?

Your healthcare provider may give you other instructions about how to manage your DCM.

• Your healthcare provider may want to treat you for other heart conditions. This might include medicines for high blood pressure or high cholesterol
• Talk with your healthcare provider about what kinds of exercise are OK for you.
• You might need other lifestyle changes, like losing weight, quitting smoking, or improving your diet. You may need to restrict salt.
• You may need to reduce your intake of alcohol or caffeine. These increase the risk of abnormal heart rhythms.
• Monitor your symptoms carefully. If you are gaining weight quickly, it might be a sign of increased fluid retention due to poor heart function.

When should I call my healthcare provider?

See a healthcare provider right away if you have severe symptoms like chest pain or severe shortness of breath. See your healthcare provider if you gain excessive weight. If your symptoms are gradually increasing, see your healthcare provider soon.

Key points

DCM affects the heart muscle. The heart enlarges and becomes thin, making it unable to pump as well. It can make the heart unable to pump enough blood. It can also sometimes lead to dangerous heart rhythms and fluid retention. It is important that you:

• Follow your healthcare provider’s instructions carefully. Take all of your medicines as prescribed.
• See your healthcare provider for regular check-ups. This is important even if you do not have any symptoms.
• Some people with DCM may not need a lot of treatment, in the early stages. However, some people do need multiple medicine or procedures.
• Tell your healthcare provider if your symptoms are severe or get worse.
• Other family members may need to be checked for DCM, especially if the cause of your disease is unknown.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your provider tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your provider if you have questions.