Restrictive cardiomyopathy is rare in the
United States and most other industrial nations. In this disease, the
walls of the ventricles stiffen and lose their flexibility due to
infiltration by abnormal tissue. As a result, the heart cannot fill
adequately with blood and eventually loses its ability to pump
properly.
Causes
Restrictive cardiomyopathy typically
results from another disease, which occurs elsewhere in the body.
In the United States, restrictive
cardiomyopathy is most commonly related to the following: amyloidosis,
in which abnormal protein fibers (amyloid) accumulate in the heart's
muscle; sarcoidosis, an inflammatory disease that causes the formation
of small lumps in organs; and hemochromatosis, an iron overload of the
body, usually due to a genetic disease.
In general, restrictive cardiomyopathy
does not appear to be inherited; however, some of the diseases that
lead to the condition are genetically transmitted
Symptoms
Typical signs of the condition include
symptoms of congestive heart failure: weakness, fatigue, and
breathlessness. Swelling of the legs, caused by fluid retention,
occurs in a significant number of patients. Other symptoms include
nausea, bloating, and poor appetite, probably because of the retention
of fluid around the liver, stomach, and intestines
Diagnosis
A physician may suspect restrictive
cardiomyopathy based on a patient's symptoms and the presence of
another disease. Although symptoms of congestive heart failure may
predominate, the size of the heart remains relatively small, unlike
other cardiomyopathies.
Diagnostic information comes from an
electrocardiogram or any of several imaging studies that provide
pictures of the heart. These include echocardiography, magnetic
resonance imaging, and computed tomography.
A definite diagnosis usually requires
cardiac catheterization studies or a biopsy, in which a tiny
piece of tissue--including heart muscle--is removed for laboratory
analysis.
Treatment
Restrictive cardiomyopathy has no
specific treatment. The underlying disease that leads to the heart
problem also may not be treatable.
In general, the use of traditional
heart drugs has been limited in this cardiomyopathy, although
diuretics may help control fluid accumulation.
In rare cases, surgery is sometimes
used to try to improve blood flow into the heart.
Course of the disease
The condition is similar to
congestive cardiomyopathy
and tends to worsen with time. Only about 30 percent of patients
survive more than 5 years after diagnosis.
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