Restrictive cardiomyopathy
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.
The interior of the heart is composed of valves, chambers, and associated vessels.
The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.
Causes
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:
- Cardiac amyloidosis
- Carcinoid heart disease
- Diseases of the heart lining (endocardium), such as endomyocardial fibrosis and Loeffler syndrome (rare)
- Iron overload (hemochromatosis)
- Sarcoidosis
- Scarring after radiation or chemotherapy
- Scleroderma
- Tumors of the heart
Cardiomyopathy, also known as myocardiopathy, is a condition that includes diseases of the heart muscle, resulting in abnormal heart function. It is a progressive impairment of the structure and function of the muscular walls of the heart chambers, and is distinguished from heart muscle impairment caused by hypertension, coronary atherosclerosis, valvular dysfunction, or abnormalities of the pericardium. Cardiomyopathy may be caused by many disorders, or it may be idiopathic (of unknown cause). The main types of cardiomyopathies are dilated, hypertrophic, and restrictive. Cardiomyopathies often cause symptoms of heart failure. Some cardiomyopathies may also cause chest pain, fainting, arrhythmia, or sudden death. Treatment of cardiomyopathies, in addition to lifestyle changes, includes drug therapy with beta-blockers, diuretics, anticoagulants and antiarrhythmics, surgical intervention, pacemaker therapy, and in high-risk patients, implantable cardioverter defibrillator to prevent sudden cardiac death. Cardiac transplantation is an option for patients who do not respond to any of these treatment options.
Symptoms
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:
- Cough
- 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
- Enlarged liver
- 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:
- Cardiac catheterization and coronary angiography
- Chest CT scan
- Chest x-ray
- ECG (electrocardiogram)
- Echocardiogram and Doppler study
- MRI of the heart
- Nuclear heart scan (MUGA, RNV, PET)
- Serum iron studies
- Serum and urine protein tests
Restrictive cardiomyopathy may appear similar to constrictive pericarditis. Cardiac catheterization may help confirm the diagnosis. Rarely, a biopsy of the heart may be required.
Treatment
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
- Chemotherapeutic agents
- Medicines such as tafamidis that target abnormal proteins (amyloid fibrils)
- Liver transplantation
Additional treatments are also under investigation.
A heart transplant may be considered if the heart function is very poor and symptoms are severe.
Outlook (Prognosis)
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
Contact your health care provider if you have symptoms of restrictive cardiomyopathy.
References
Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA guideline for the management of heartfailure: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol. 2022;79(17):1757-1780. PMID: 35379504
Hershberger RE. The dilated, restrictive, and infiltrative cardiomyopathies. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 52.
McKenna WJ, Elliott PM. Diseases of the myocardium and endocardium. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 54.
Version Info
Last reviewed on: 5/8/2022
Reviewed by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
