Restrictive Cardiomyopathy

Topic Overview

What is restrictive cardiomyopathy?

Restrictive cardiomyopathy is a serious problem that makes your heart muscle stiff. When your heart muscle is stiff, it can't stretch to allow enough blood to enter its lower chambers, the ventricles. So blood that would normally enter the heart backs up in your circulatory system.

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 restrictive cardiomyopathy?

Often the cause is never found. But we do know that there are a number of diseases or problems that can lead to restrictive cardiomyopathy. These include:

• Cardiac amyloidosis, a buildup of an abnormal protein in the heart muscle.
• Hemochromatosis, a buildup of iron in the heart muscle.
• Sarcoidosis, a rare type of heart inflammation.
• Radiation therapy and chemotherapy, used to treat cancer.
• Carcinoid syndrome, a rare disease that causes certain chemicals to be released into the blood stream. These chemicals can stiffen heart muscle.
• Löeffler’s syndrome and endomyocardial fibrosis, conditions that can cause scar tissue in the heart.
• Genetic factors. You can inherit diseases, including Gaucher disease and Fabry's disease, that can lead to restrictive cardiomyopathy. But these diseases can be treated to prevent restrictive cardiomyopathy.

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.

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 restrictive 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:

• Electrocardiogram, also known as an ECG or EKG.
• Chest X-ray.
• Echocardiogram.
• Routine blood tests.

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 restrictive 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.
• Limit your physical activity. Talk to your doctor about the best balance of rest and activity.
• 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 or implantable cardioverter-defibrillator (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 3 lb (1.4 kg) 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 restrictive cardiomyopathy?

Most of the time, restrictive 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. If your doctor finds the cause of your restrictive cardiomyopathy, then the cause will also be treated, if possible.

Some people develop other problems, including:

• Stroke.
• Heart attack.
• A blood clot in the lung, called a pulmonary embolism.
• 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 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

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	Heart failure: Avoiding medicines that make symptoms worse
	Heart failure: Avoiding triggers for sudden heart failure
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	Heart failure: Watching your fluids
	Low-salt diets: Eating out

Symptoms

Symptoms of restrictive cardiomyopathy are usually the same as those typically seen in heart failure and include:

• Weight gain caused by water retention and fluid buildup (edema), especially in the legs, ankles, and feet.
• Abdominal swelling, tenderness, or pain, which may result from the buildup of fluid in the abdomen (ascites) and from blood that backs up in the liver.
• Difficulty breathing during normal activities or exercise that did not cause breathing problems before.
• A dry, hacking cough, especially when lying down. At night, you may wake up coughing with a rapid heart rate and a feeling of being suffocated (paroxysmal nocturnal dyspnea).
• Dizziness, fainting, or feeling tired or weak.
• Heart palpitations.
• Increased urination at night.

Sudden heart failure can develop, causing congestion and rapid fluid buildup in the lungs (pulmonary edema). This is an emergency medical situation and requires immediate care. Symptoms develop quickly and include:

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

Sudden heart failure is different from gradual heart failure and may be triggered by:

• Eating too much salt.
• Not following directions for taking medicines.
• An irregular or rapid heartbeat that comes on suddenly.
• Having a heart attack.
• Drinking alcohol or taking drugs like cocaine.

Complications of restrictive cardiomyopathy can also be very serious. They include:

• A blood clot that develops in the heart. The clot can break loose, travel through the bloodstream, become lodged in a blood vessel, and block blood supply to:
  • The brain, resulting in a stroke.
  • The heart, causing a heart attack.
  • The lungs, causing a pulmonary embolism.
  • A limb or elsewhere in the body, possibly causing a loss of circulation and tissue damage.
• Episodes of rapid, abnormal heart rhythms (arrhythmia), especially atrial fibrillation.
• Sudden cardiac death.

Exams and Tests

If restrictive cardiomyopathy is identified correctly and right away, symptoms can be treated more successfully. To diagnose restrictive cardiomyopathy, your doctor will ask about your medical history. Be prepared to discuss any conditions or diseases that you or your family members have had. In addition, you should be able to describe your symptoms and how often you experience them.

Your doctor will also do a thorough physical examination, including listening to your heart and lungs with a stethoscope. Signs of heart failure can include:

• Unusual sounds, heart murmurs, or extra sounds called gallops, 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 (edema), especially in the legs and feet.
• Bulging neck veins.

It is important to remember that people of all ages can develop restrictive cardiomyopathy. When symptoms of cardiomyopathy first occur, several tests can help your doctor diagnose whether another condition, such as sarcoidosis (the formation of nodules) or hemochromatosis (a buildup of iron in the heart muscle), is causing symptoms.

Echocardiogram: An echocardiogram, sometimes called an echo, is an ultrasound exam that uses high-pitched sound waves to create an image of the heart on a television screen. This painless and noninvasive test—which determines if your lower heart chambers (ventricles) are filling too rapidly, a specific sign of restrictive cardiomyopathy—is the easiest way to diagnose restrictive cardiomyopathy.

Electrocardiogram: An electrocardiogram (ECG, EKG) records the electrical activity in the heart as impulses move through it during contraction and relaxation. An electrocardiogram can determine whether heart muscle is damaged and may also suggest other possible causes of cardiomyopathy, such as a heart attack or a buildup of protein in the heart muscle (cardiac amyloidosis).

Chest X-ray: A chest X-ray shows the size and shape of the heart and whether there is fluid buildup in the lungs. In a heart affected by restrictive cardiomyopathy, the upper heart chambers (atria) may sometimes appear enlarged, although usually the overall heart size is normal or only slightly enlarged.

Imaging tests: More complex tests, called magnetic resonance imaging (MRI) and computed tomography (CT), may be used to evaluate restrictive cardiomyopathy. The major benefit of these tests is that they can help distinguish between restrictive cardiomyopathy and constrictive pericarditis. If the sac around the heart (pericardium) is thickened, the symptoms are more likely due to constrictive pericarditis than to restrictive cardiomyopathy.

Cardiac catheterization or coronary angiogram: During cardiac catheterization, a thin, flexible tube called a catheter is threaded through an artery or vein in the arm or groin and into the blood vessels of the heart to measure pressure in the heart chambers. In restrictive cardiomyopathy, there is typically a higher-than-normal pressure inside the heart chambers. Dye can also be injected through the catheter to see how the heart chambers are pumping and whether heart valves are leaking. The process of injecting dye into the coronary arteries is called coronary angiography. Cardiac catheterization may help determine whether you have constrictive pericarditis or restrictive cardiomyopathy.

Other procedures: Sometimes a sample (biopsy) of the heart tissue—usually done during cardiac catheterization—or the pericardium is the only way to determine the cause of restrictive cardiomyopathy (for example, whether it is caused by hemochromatosis or sarcoidosis).

Treatment Overview

In most cases, restrictive cardiomyopathy is a progressive disease in which the cause of the disease is not known (idiopathic restrictive cardiomyopathy) and so cannot be directly treated. Typically, the heart muscle continues to stiffen and lose function and strength, and heart failure (inability of the heart to pump enough blood) develops. In these cases, treatment involves trying to decrease the heart's workload.

In some cases the cause of restrictive cardiomyopathy can be identified, such as in carcinoid syndrome, sarcoidosis, and amyloidosis, although the treatment is generally ineffective. Corticosteroids may offer limited benefit in treating sarcoidosis and amyloidosis. In most of these cases, the condition is progressive, and treatment involves trying to manage heart failure symptoms.

But in other cases where the cause is diagnosed early and can be treated, further heart damage may be prevented. For example, in restrictive cardiomyopathy caused by hemochromatosis (a buildup of iron in the heart muscle), treatment may involve the use of drugs that help eliminate excess iron (chelating agents) and/or phlebotomy (withdrawing blood). In another example, an inherited problem called Fabry's disease can be treated to prevent restrictive cardiomyopathy from happening.

If heart failure has developed, your doctor will prescribe medicines to manage its symptoms and complications. They may include:

• Diuretics, which help eliminate fluid buildup in the lungs and elsewhere in the body.
• Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) to improve blood flow and reduce the heart's workload. ARBs may be used when a person cannot tolerate ACE inhibitors or when ACE inhibitors are not controlling symptoms.
• Beta-blockers, which slow the heart rate and reduce blood pressure.
• Anticoagulants, to help prevent blood clots from forming in the heart. People with restrictive cardiomyopathy, especially those with atrial fibrillation, are at risk for developing clots, which can travel through the bloodstream to other places in the body and cause a heart attack, pulmonary embolism, or stroke.
• Digoxin, which can help increase the strength of heart contractions. These medicines are sometimes used, although with caution in those people who have amyloidosis, because they can lead to serious arrhythmias.
• Calcium channel blockers, which slow your heart rate and lower blood pressure. These medicines may be used to treat diastolic heart failure, when the heart has problems filling with blood.

Surgery

An artificial pacemaker may be surgically placed in the chest. Scar tissue that develops in restrictive cardiomyopathy may block electrical impulses traveling through the heart and result in abnormal heartbeats, called arrhythmias. Pacemakers stimulate the heart muscle to beat regularly when the electrical signals from the top of the heart are blocked.

An implantable cardioverter-defibrillator (ICD) is another small device that may be surgically placed 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.

A heart transplant is available to a small number of people who have severe end-stage restrictive cardiomyopathy and 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.

Stem cell transplantation may be used for amyloidosis (a buildup of protein), although the long-term benefits are not known.

Home Treatment

While medical care is important in treating restrictive cardiomyopathy, the following self-care recommendations are also critical.

• Limit alcohol. Drink moderately, which is 2 drinks a day or less for men or 1 drink a day or less for women. Long-term overuse of alcohol may increase the risk of developing cardiomyopathy in some people.
• Restrict salt (sodium) in your diet. The body attempts to compensate for heart failure by retaining salt and water. This leads to fluid buildup and swelling. For more information, see:

  Heart failure: Eating less salt.

  Low-salt diets: Eating out.

• Limit fluids if your doctor tells you to. Talk to your doctor about how much fluid is safe for your specific condition. For more information, see:

  Heart failure: Watching your fluids.

• Weigh yourself daily. If fluid begins to build up rapidly, you will notice a sudden weight gain. Your doctor may tell you how much weight to watch for. But in general, call your doctor if you gain 3 lb (1.4 kg) or more in 2 to 3 days. For more information, see:

  How do I check my weight?.

• Limit your physical activity. People with restrictive cardiomyopathy may need to avoid overexertion because their hearts are not able to increase blood flow during exercise. Talk to your doctor about the best balance of rest and activity for your specific condition.
• Avoid triggers for sudden heart failure. For more information, see:

  Heart failure: Avoiding triggers for sudden heart failure.

• Take your medicines as directed. If you don't, your heart failure may get worse, or you may develop sudden heart failure. For more information, see:

  Heart failure: Taking medicines properly.

• Be careful using nonprescription medicines. Some medicines can make your heart failure worse. For more information see:
  • Heart failure: Avoiding medicines that make symptoms worse.

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

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Organizations

Related Information

• Coronary Artery Disease
• Dilated Cardiomyopathy
• Heart Failure
• Hypertrophic Cardiomyopathy
• Pericarditis

References

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.
• Hoit BD, Gupta S (2008). Restrictive, obliterative, and infiltrative cardiomyopathies. In V Fuster et al., eds., Hurst's The Heart, 12th ed., pp. 851–862. New York: McGraw-Hill Medical.
• 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.

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