Dilated Cardiomyopathy

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Dilated Cardiomyopathy

Topic Overview

Illustration of the heart

What is dilated cardiomyopathy?

Dilated cardiomyopathy is a serious condition that weakens your heart muscle and causes it to stretch, or dilate. When your heart muscle is weak, it can't pump out blood as well as it should, so more blood stays in your heart after each heartbeat. As more blood fills and stays in the heart, the heart muscle stretches even more and gets even weaker.

Most of the time, this leads to heart failure. Heart failure does not mean that your heart stops pumping. It means that your heart can't pump enough blood to meet your body's needs.

What causes dilated cardiomyopathy?

The most common type of dilated cardiomyopathy develops after a heart attack has damaged the heart muscle. But it can also be caused by many diseases or problems that may or may not be related to your heart. Sometimes the cause is not known.

Some of the things that can lead to dilated cardiomyopathy include:

  • Coronary artery disease and heart attack.
  • High blood pressure, which can put stress on the heart walls.
  • Heart valve diseases, including aortic valve regurgitation and mitral valve regurgitation.
  • Myocarditis, which is inflammation of the heart muscle. It is caused by a virus or an immune system problem.
  • Drinking too much alcohol, using certain illegal drugs such as cocaine, or taking certain medicines such as chemotherapy.
  • Being exposed to toxic metals, such as lead or mercury.
  • Being pregnant. In rare cases, dilated cardiomyopathy develops toward the end of pregnancy or during the first 6 months after a woman gives birth. Experts don't know why this happens.

What are the symptoms?

You may not have any symptoms at first. Or you may have mild symptoms, such as feeling very tired or weak.

If your heart gets weaker, you will develop heart failure. When this happens, you will feel other symptoms, including:

  • Shortness of breath, especially with activity.
  • Tiredness.
  • Trouble breathing when you lie down.
  • Swelling in your legs.
  • Chest pain.

You may get these symptoms slowly, over months or years. Or you may get them suddenly, such as after pregnancy or an illness caused by a virus.

Heart failure that suddenly gets worse is an emergency. Get medical help right away if you:

  • Have severe shortness of breath.
  • Have a fast or uneven heartbeat.
  • Cough up foamy, pink mucus.
  • Have chest pain.

How is dilated cardiomyopathy diagnosed?

Your doctor will ask questions about your symptoms and past health. He or she will want to know about recent illnesses and about heart disease in your family. Your doctor will listen to your heart and lungs and check your legs for fluid buildup.

You may also have other tests, including:

In some cases, a doctor may want to look at a small sample of heart tissue, called a biopsy, to make a definite diagnosis.

How is it treated?

You will probably need to take several medicines to treat heart failure caused by dilated cardiomyopathy. It is very important to take your medicines exactly as your doctor tells you to and to keep taking them. If you don't, your heart failure could get worse.

Lifestyle changes are an important part of your treatment. Taking these steps can help slow down heart failure.

  • Limit how much salt you eat. Salt causes water to build up in your body and makes it harder for your heart to pump. Limit your fluid intake if your doctor tells you to.
  • Get regular exercise. Your doctor can tell you what level of exercise is safe for you, how to check your pulse rate, and how to know if you are doing too much.
  • Limit how much alcohol you drink.

Your doctor may suggest a mechanical device to help your heart pump blood or prevent life-threatening irregular heart rhythms. Such devices include a pacemaker, implantable cardioverter-defibrillator (ICD), or a combination pacemaker and ICD. If your condition is very bad, a heart transplant may be an option.

Keeping track of your symptoms every day is an important part of your treatment. Call your doctor if:

  • You have a sudden weight gain such as 1.5 kg (3 lb) or more in 2 to 3 days.
  • Your ability to exercise changes.
  • You have any sudden change in your symptoms.

What can you expect with dilated cardiomyopathy?

Most of the time, dilated cardiomyopathy leads to heart failure. Heart failure usually gets worse over time, but treatment can slow the disease and help you feel better and live longer. In more and more cases, the problem is being found earlier, when it can be better managed.

Some people develop other problems, including:

  • Stroke.
  • Heart attack.
  • Sudden cardiac death, which means the heart suddenly stops working. This may be more likely to happen to people who have serious rhythm problems (arrhythmias) in one of the lower heart chambers (ventricles).

If a woman gets dilated cardiomyopathy from pregnancy, she should not get pregnant again. This is true even if her heart problem later gets better.

If your disease is getting worse over time, you may want to think about making end-of-life decisions. It can be comforting to know that you will get the type of care you want.

Frequently Asked Questions

Learning about dilated cardiomyopathy:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Living with dilated cardiomyopathy:

End-of-life issues:


At first you may not feel any symptoms of dilated cardiomyopathy, or symptoms such as fatigue or weakness may be mild.

Eventually, you will develop heart failure. Symptoms of heart failure can develop gradually, over months or years. In other instances, heart failure may develop suddenly, such as after a viral infection or pregnancy.

Symptoms of gradual heart failure

Typically, symptoms of heart failure develop gradually and may include:

  • Weakness and fatigue.
  • Difficulty breathing and/or wheezing during normal activities or exercise that did not cause breathing problems in the past.
  • Shortness of breath.
  • A dry, hacking cough, especially when lying down.
  • Fluid buildup (edema), especially in the legs, ankles, and feet.
  • Dizziness, fainting, or feeling tired or weak.
  • Heart palpitations.
  • Rapid weight gain caused by water retention.
  • Increased urination at night.
  • Abdominal swelling, tenderness, or pain, which may result from a buildup of fluid in the body (ascites) and blood that backs up in the liver.

Symptoms of sudden heart failure

In sudden heart failure, rapid fluid buildup in the lungs may cause symptoms of pulmonary edema, such as:

  • Severe shortness of breath.
  • Irregular or rapid heartbeat.
  • Coughing up foamy, pink mucus.

Sudden heart failure is an emergency medical situation and requires immediate care.

Complications of dilated cardiomyopathy

Complications of dilated cardiomyopathy may include:

  • Pulmonary edema, which is rapid fluid buildup in the lungs.
  • Arrhythmias, which are abnormal heart rhythms that can cause loss of consciousness or sudden death.
  • Blood clots inside the heart, which can lead to a stroke or heart attack.

Dilated cardiomyopathy is the most common type of cardiomyopathy. Other forms of cardiomyopathy include restrictive cardiomyopathy, in which the heart muscle gets stiff, and hypertrophic cardiomyopathy, in which the heart muscle is thickened and can't relax. For more information, see the topics Hypertrophic Cardiomyopathy and Restrictive Cardiomyopathy.

Examinations and Tests

The first step in diagnosing dilated cardiomyopathy is a review of your medical history. Your doctor will ask about any recent illnesses, your alcohol and drug consumption, and your family history of heart disease.

Then he or she will do a thorough physical examination, including listening to your heart and lungs with a stethoscope. Heart failure usually develops with dilated cardiomyopathy, so your doctor will look for signs of heart failure, including:

  • Unusual sounds, called heart murmurs, which may mean you have a problem with the heart's walls or valves. Pulmonary rales—crackles or bubbling sounds—heard in the chest may mean there is fluid buildup in the lungs.
  • Fluid buildup may also be noted in the extremities, especially the legs and feet, and in bulging neck veins.

The following tests may also be done.

Echocardiogram: An echocardiogram is an ultrasound examination that uses high-pitched sound waves to create an image of the heart on a television screen. This painless and non-invasive test is the best and easiest way to diagnose dilated cardiomyopathy.

An echocardiogram, sometimes called an echo, estimates the heart's ejection fraction, a measurement of the heart's efficiency and the function of the left ventricle, the main pumping chamber. It also helps evaluate heart valve function and the shape and thickness of the heart chamber walls, which if stretched may indicate dilated cardiomyopathy.

Electrocardiogram: An electrocardiogram (ECG, EKG) is a record of the heart's electrical activity, including any abnormal heart rhythms (arrhythmias) resulting from dilated cardiomyopathy. It may also reveal areas that have been damaged by a heart attack.

Your doctor may also use a Holter monitor, a type of portable electrocardiogram that monitors your heart's electrical activity over a longer period of time (usually 24 hours). This may be done to check for any arrhythmias resulting from dilated cardiomyopathy.

Chest X-ray: A chest X-ray can show whether your heart is enlarged and whether there is fluid buildup in your lungs, a sign of heart failure.

Radionuclide ventriculogram: Radionuclide ventriculogram, also called nuclear scanning, measures ejection fraction. This is a useful diagnostic measurement because the ejection fraction is diminished in dilated cardiomyopathy.

During this test, a tiny dose of a radioactive substance (radioisotope) is injected into a vein. The movement of the gamma rays emitted by the radioisotope is followed through the heart chambers with a gamma camera, and the images are analyzed by a computer.

Coronary angiogram or coronary catheterization: In a coronary angiogram/catheterization, a thin, flexible tube is threaded through an artery or vein in the arm or groin and into the heart to measure pressure in the heart chambers and take samples of blood. Dye can also be injected through the catheter to see whether the arteries that supply the heart (coronary arteries) are blocked, how the heart chambers are pumping, and whether heart valves are leaking.

A myocardial biopsy, a sample of heart tissue, can be taken through the catheter and examined for signs of infection, metabolic disease, or a tumour. This procedure is usually reserved for people who have acute heart failure and who are not responding to treatment.

Electrophysiology study: An electrophysiology study (EP, EPS) is another way to study the heart's electrical activity. EP studies are used to evaluate arrhythmias or syncope and to assess the risk of sudden cardiac death.

For more information about examinations and tests, see the topic Heart Failure.

Treatment Overview

In most cases, treatment for dilated cardiomyopathy is done to relieve symptoms, improve heart function, and help you live longer. The majority of people will need to take a number of medicines along with making healthy lifestyle changes. Surgical procedures may also be considered, especially when medicines do not improve your condition.

In some cases, the cause of the condition can be successfully addressed, such as when dilated cardiomyopathy is caused by excessive alcohol consumption. Limiting how much you drink may help prevent the disease from progressing.

But in viral myocarditis (inflammation of the heart muscle caused by a virus), there are no medicines to attack the viruses that cause dilated cardiomyopathy.


Medicines used to treat heart failure caused by dilated cardiomyopathy include:

  • Angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), and vasodilators, which widen blood vessels to improve blood flow and reduce the heart's workload. ACE inhibitors are considered the basis of therapy for dilated cardiomyopathy. They specifically have been shown to improve symptoms and prolong life in people who have heart failure. ARBs may be used when a person cannot tolerate ACE inhibitors or the medicine is not controlling symptoms. Other vasodilators may be used when a person cannot tolerate ACE inhibitors or ARBS or the medicines are not controlling symptoms.
  • Beta-blockers, which slow the heart rate and reduce blood pressure. The heart can pump more efficiently when it has more time to relax. Adding beta-blockers to standard treatment with ACE inhibitors may reduce the rate of hospitalization or death in people with moderate or severe heart failure.
  • Diuretics, to help remove excess fluid from the body. Spironolactone is a diuretic that prevents potassium loss and has been shown to prolong life in people with severe forms of heart failure.
  • Digoxin, which can help increase the strength of the heart muscle contraction, improve blood flow, and reduce symptoms of heart failure.
  • Anticoagulants, such as warfarin (for example, Coumadin) and heparin, to prevent blood clots that can develop when blood is not being pumped efficiently through the heart and out to the rest of the body. Blood clots may lead to strokes or heart attack. People with both dilated cardiomyopathy and atrial fibrillation are at higher risk for developing blood clots.
  • Antiarrhythmics, such as amiodarone, which control the heart rate when abnormal, rapid heartbeats (arrhythmias) are present.

For more information on these medicines, see the topic Heart Failure.


A pacemaker for heart failure (also called cardiac resynchronization therapy) may be surgically placed in the upper chest. This pacemaker helps your heart pump blood. This pacemaker makes both lower chambers of the heart (ventricles) pump blood at the same time. Because both ventricles beat at the same time, this pacemaker is also called a biventricular pacemaker. It can help you feel better so you can be more active. It also can help keep you out of the hospital and help you live longer.1 Sometimes this pacemaker is combined with an implantable cardioverter-defibrillator (ICD) to prevent sudden death from a life-threatening irregular heartbeat. For help on the decision to get a pacemaker, see:

Click here to view a Decision Point. Heart Failure: Should I Get a Pacemaker (Cardiac Resynchronization Therapy)?

An implantable cardioverter-defibrillator (ICD) is a small device that is surgically implanted in the chest. It is used to lower the risk of sudden death from life-threatening irregular heart rhythms (arrhythmias). An ICD continuously monitors your heart. If it detects a life-threatening rapid heart rhythm, it sends an electric shock to your heart to restore a normal rhythm. You may need an ICD if you have had a serious episode of life-threatening irregular heart rhythm or are at high risk for having one. For help on the decision to get an ICD, see:

Click here to view a Decision Point. Heart Failure: Should I Get an Implantable Cardioverter-Defibrillator (ICD)?

Ventricular assist devices (VADs), also known as heart pumps, are mechanical pumping devices that are inserted into the chest to help the heart pump more blood. VADs are typically used to keep people alive until a donor heart is available for transplant. Rarely, VADs may be used as an alternative to heart transplant for long-term treatment of severe heart failure. These devices require surgery to place the device and to make the connections between the heart and the device. See picture of a ventricular assist device.

A heart transplant is the only cure for dilated cardiomyopathy. But a transplant is available to a small number of people who meet specific criteria for transplantation. The diseased heart is removed and replaced with a healthy heart donated by a person who has recently died. There are limited donor hearts available.

Mitral valve repair or replacement. This surgery is standard practice for mitral valve problems, but not for dilated cardiomyopathy. Sometimes, dilated cardiomyopathy can lead to mitral valve regurgitation. Surgery on the mitral valve can treat the regurgitation, but it does not cure dilated cardiomyopathy.

Home Treatment

Even though medical care is very important in treating dilated cardiomyopathy, the following self-care recommendations are also important.

Pregnancy can be dangerous for people with dilated cardiomyopathy. If you have dilated cardiomyopathy and are considering becoming pregnant, talk to your doctor.

For more information on home treatment, see the topic Heart Failure.

Other Places To Get Help


Canadian Cardiovascular Society
222 Queen Street
Suite 1403
Ottawa, ON  K1P 5V9
Phone: 1-877-569-3407 toll-free
(613) 569-3407
Fax: (613) 569-6574
Web Address: www.ccs.ca

The Canadian Cardiovascular Society works to advance the cardiovascular health and care of Canadians through leadership, research, and advocacy.

Heart and Stroke Foundation of Canada
222 Queen Street
Suite 1402
Ottawa, ON  K1P 5V9
Phone: (613) 569-4361
Fax: (613) 569-3278
Web Address: www.heartandstroke.ca

The Heart and Stroke Foundation of Canada works to improve the health of Canadians by preventing and reducing disability and death from heart disease and stroke through research, health promotion, and advocacy.

Heart Rhythm Society
1400 K Street NW
Suite 500
Washington, DC  20005
Phone: (202) 464-3400
Fax: (202) 464-3401
Web Address: www.hrsonline.org

The Heart Rhythm Society provides information for patients and the public about heart rhythm problems. The Web site includes a section that focuses on patient information. This information includes causes, prevention, tests, treatment, and patient stories about heart rhythm problems. You can use the Find a Specialist section of the Web site to search for a heart rhythm specialist practicing in your area.

HeartHub for Patients
Web Address: www.hearthub.org

HeartHub for Patients is a website from the American Heart Association. It provides patient-focused information, tools, and resources about heart diseases and stroke. The site helps you understand and manage your health. It includes online tools that explain your risks and treatment options. The site includes articles, the latest news in health and research, videos, interactive tools, forums and community groups, and e-newsletters.

The website includes health centers that cover heart rhythm problems, cardiac rehabilitation, caregivers, cholesterol, diabetes, heart attack, heart failure, high blood pressure, peripheral artery disease, and stroke.

HeartHub for Patients also links to Heart360.org, another American Heart Association website. Heart360 is a tool that helps you send and receive medical information with your doctor. It also helps you monitor your health at home. It gives you access to tools to manage and monitor high blood pressure, diabetes, high cholesterol, physical activity, and nutrition.

U.S. National Heart, Lung, and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD  20824-0105
Phone: (301) 592-8573
Fax: (240) 629-3246
TDD: (240) 629-3255
Email: nhlbiinfo@nhlbi.nih.gov
Web Address: www.nhlbi.nih.gov

The U.S. National Heart, Lung, and Blood Institute (NHLBI) information center offers information and publications about preventing and treating:

  • Diseases affecting the heart and circulation, such as heart attacks, high cholesterol, high blood pressure, peripheral artery disease, and heart problems present at birth (congenital heart diseases).
  • Diseases that affect the lungs, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema, sleep apnea, and pneumonia.
  • Diseases that affect the blood, such as anemia, hemochromatosis, hemophilia, thalassemia, and von Willebrand disease.



  1. McKelvie R (2010). Heart failure, search date May 2009. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.

Other Works Consulted

  • Hare JM (2008). The dilated, restrictive, and infiltrative cardiomyopathies. In P Libby, ed., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed., vol. 2, pp. 1739–1761. Philadelphia: Saunders Elsevier.
  • Hunt SA, et al. (2009). 2009 focused update incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management of heart failure in adults. A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation, 119(14): e391–e479.
  • Mestroni L, et al. (2008). Dilated cardiomyopathies. In V Fuster et al., eds., Hurst's the Heart, 12th ed., pp. 803–821. New York: McGraw-Hill.


By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Primary Medical Reviewer Andrew Swan, MD, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer George Philippides, MD - Cardiology
Last Revised October 4, 2010

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.