Restrictive cardiomyopathy refers to a group of disorders in which the heart chambers are unable to properly fill with blood because of stiffness in the heart.

In restrictive cardiomyopathy, the heart is of normal size or only slightly enlarged. However, it cannot relax normally during the time between heartbeats when the blood returns from the body to the heart (diastole).

Later in the disease, the heart may not pump blood efficiently. The abnormal heart function can affect the lungs, liver, and other body systems. Restrictive cardiomyopathy may affect either or both ventricles. It may be associated with a disease of the heart muscle.

The most common causes of restrictive cardiomyopathy are amyloidosis and scarring of the heart from an unknown cause (idiopathic myocardial fibrosis). It frequently occurs 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's syndrome (rare)
• Radiation fibrosis
• Sarcoidosis
• Scleroderma
• Tumors of the heart

• Cough
• Difficulty breathing
  • At night
  • Especially with exertion
  • When lying flat
• Fatigue, poor exercise tolerance
• Swelling of the abdomen
• Swelling of the feet and ankles

An examination may show:

• Signs of heart failure
• Fluid backup into the lungs, hands and feet, gastrointestinal tract, and liver
• Distended neck veins
• Lung crackles and abnormal or distant heart sounds when listening to the chest with a stethoscope (auscultation)

Tests for restrictive cardiomyopathy include:

• Chest CT scan
• Chest MRI scan
• Chest x-ray
• Coronary angiography
• ECG (electrocardiogram)
• Echocardiogram and Doppler study

Restrictive cardiomyopathy may be hard to tell apart from constrictive pericarditis. A biopsy of the heart muscle or cardiac catheterization may help confirm the diagnosis.

Few treatmetns are known to be effective for restrictive cardiomyopathy. The goal of treatment is to control symptoms and improve the quality of life.

The following treatments may be used to control symptoms:

• Chemotherapy
• Diuretics to remove fluid and help improve breathing
• Steroids

A heart transplant may be considered if the heart function is very poor.

People with restrictive cardiomyopathy may be heart transplant candidates. The outlook depends on the cause of the condition, but it is usually poor. Average survival after diagnosis is 9 years.

• Mitral regurgitation
• Progressive heart failure
• Tricuspid regurgitation

Call your health care provider if you have symptoms of restrictive cardiomyopathy.

Hare JM. The Dilated, Restrictive, and Infiltrative Cardiomyopathies. In: Libby P, Bonow RO, Mann DL, Zipes DP. Libby: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 64.