Cardiomyopathy - restrictive; Infiltrative cardiomyopathy; Idiopathic myocardial fibrosis
Restrictive cardiomyopathy refers to a set of changes in how the heart muscle functions. These changes cause the heart to fill poorly (more common) or squeeze poorly (less common). Sometimes, both problems are present.
In a case of restrictive cardiomyopathy, the heart muscle is of normal size or slightly enlarged. Most of the time, it also pumps normally. However, it does not relax normally during the time between heartbeats when the blood returns from the body (diastole).
Although the main problem is abnormal filling of the heart, the heart may not pump blood strongly when the disease progresses. The abnormal heart function can affect the lungs, liver, and other body systems. Restrictive cardiomyopathy may affect either or both of the lower heart chambers (ventricles). Restrictive cardiomyopathy is a rare condition. The most common causes are amyloidosis and scarring of the heart from an unknown cause. It also can occur after a heart transplant.
Other causes of restrictive cardiomyopathy include:
- Carcinoid heart disease
- Diseases of the heart lining (endocardium), such as endomyocardial fibrosis and Loeffler syndrome (rare)
- Iron overload (hemochromatosis)
- Scarring after radiation or chemotherapy
- Tumors of the heart
Symptoms of heart failure are most common. These symptoms often develop slowly over time. However, symptoms sometimes start very suddenly and are severe.
Common symptoms are:
- Breathing problems that occur at night, with activity or when lying flat
Fatigue and inability to exercise
- Loss of appetite
Swelling of the abdomen
Swelling of the feet and ankles
- Uneven or rapid pulse
Other symptoms may include:
- Chest pain
- Inability to concentrate
- Low urine output
- Need to urinate at night (in adults)
Exams and Tests
A physical exam may show:
Enlarged (distended) or bulging neck veins
Lung crackles and abnormal or distant heart sounds in the chest heard through a stethoscope
Fluid backup into the hands and feet
Signs of heart failure
Tests for restrictive cardiomyopathy include:
Restrictive cardiomyopathy may appear similar to constrictive pericarditis. Cardiac catheterization may help confirm the diagnosis. Rarely, a biopsy of the heart may be required.
The condition causing the cardiomyopathy is treated when it can be found.
Few treatments are known to work well for restrictive cardiomyopathy. The main goal of treatment is to control symptoms and improve quality of life.
The following treatments may be used to control symptoms or prevent problems:
- Blood thinning medicines
- Chemotherapy (in some situations)
- Diuretics to remove fluid and help improve breathing
- Medicines to prevent or control abnormal heart rhythms
- Steroids or chemotherapy for some causes
A heart transplant may be considered if the heart function is very poor and symptoms are severe.
People with this condition often develop heart failure that gets worse. Problems with heart rhythm or "leaky" heart valves may also occur.
People with restrictive cardiomyopathy may be heart transplant candidates. The outlook depends on the cause of the condition, but it is usually poor. Survival after diagnosis may exceed 10 years.
When to Contact a Medical Professional
Call your health care provider if you have symptoms of restrictive cardiomyopathy.
Hare JM. The dilated, restrictive, and infiltrative cardiomyopathies. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 65.
McKenna W, Elliott P. Diseases of the myocardium and endocardium. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 60.