What is restrictive cardiomyopathy?
Restrictive cardiomyopathy is a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expand as the ventricles fill with blood.
The pumping or systolic function of the ventricle may be normal but the diastolic function (the ability of the heart to stretch and fill with blood) is abnormal. Therefore, it is harder for the ventricles to fill with blood, and with time, the heart loses the ability to pump blood properly, because it cannot collect adequate blood to pump forward, leading to heart failure.
What are the symptoms of restrictive cardiomyopathy?
Some people with earlier forms of restrictive cardiomyopathy have no symptoms or only minor symptoms, and live a normal life. Other people develop symptoms, which progress and worsen as heart function worsens.
Symptoms occur at any age and may include:
- Shortness of breath (at first with exercise; but over time it occurs at rest)
- Fatigue (feeling overly tired)
- Inability to exercise
- Swelling of the legs and feet
- Weight gain
- Nausea, bloating, and poor appetite (related to fluid retention)
- Palpitations (fluttering in the chest due to abnormal heart rhythms)
Less common symptoms:
- Fainting (caused by irregular heart rhythms, abnormal responses of the blood vessels during exercise, or no cause may be found)
- Chest pain or pressure (occurs usually with exercise or physical activity, but can also occur with rest or after meals)
What causes restrictive cardiomyopathy?
A restrictive cardiomyopathy is not usually inherited and its cause is often unknown. Known causes may include:
- Build-up of scar tissue (idiopathic is the most common cause)
- Build-up of abnormal proteins (amyloidosis) in the heart muscle
- Chemotherapy or chest exposure to radiation
- Excess iron (hemochromatosis) in the heart
- Other systemic diseases (sarcoidosis)
- Some inherited diseases (such as Fabry's disease) may cause a build-up of abnormal molecules in the heart due to enzyme deficiency
How is restrictive cardiomyopathy diagnosed?
The size of the heart may remain relatively normal with restrictive cardiomyopathy. In some cases, restrictive cardiomyopathy may be confused with constrictive pericarditis, a condition in which the layers of the pericardium (the sac that surrounds the heart) become thickened, calcified, and stiff. Sometimes the heart may thicken, causing the inner capacity of the heart chamber to be smaller.
Restrictive cardiomyopathy is diagnosed based on medical history (your symptoms and family history), physical exam, and tests such as:
- blood tests
- chest X-ray
- exercise stress test
- cardiac catheterization
- CT scan
- radionuclide studies (Multigated Acquisition Scan)
A myocardial biopsy occasionally is done to determine the cause of cardiomyopathy, particularly to detect specific proteins or abnormal substances in the body. During a myocardial biopsy, a small tissue sample is taken from the heart and examined under a microscope to evaluate the cause of symptoms.
How is restrictive cardiomyopathy treated?
Treatment of this condition is difficult. Treatment is usually focused on treating the cause of this condition. There are specific treatments for some conditions, but may be focused on delaying disease progression. Doctors recommend lifestyle changes and medications to treat heart failure signs and symptoms.
What lifestyle changes are recommended?
Diet. Once you have symptoms such as shortness of breath or fatigue, you should restrict your intake of salt (sodium) to 2,000 mg per day. Follow this diet even when your symptoms are well controlled.
Exercise. Your doctor will tell you if you may exercise or not. While exercise is generally good for the heart, people with this form of cardiomyopathy may experience fatigue and shortness of breath, even with minimal exertion. Therefore, experts recommend that you take frequent breaks, exercise at a time of day where you have the most energy and start slow, gradually building up strength and endurance. Heavy weight lifting is not recommended.
What medications are used?
Often, medications are used to treat symptoms and prevent further complications. To manage heart failure, some people may improve by taking a beta-blocker and angiotensin-converting enzyme (ACE) inhibitor. If symptoms occur, diuretics, and aldosterone receptor inhibitors may be added. If you have an arrhythmia, your doctor may prescribe a medication to control your heart rate or lessen the occurrence of arrhythmia. Therapy may also be given to treat certain conditions, such as sarcoidosis, amyloidosis, and hemochromatosis. Your doctor will discuss what medications are best for you.
What are the surgical options?
In some cases, if the condition is severe, a heart transplant may be considered.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 9/9/2009...#12900