From Mdwiki | Restrictive cardiomyopathy | |
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| Other names: Obliterative cardiomyopathy, infiltrative cardiomyopathy, constrictive cardiomyopathy[1] | |
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| Micrograph of cardiac amyloidosis, a cause of restrictive cardiomyopathy. Congo red stain. | |
| Specialty | Cardiology |
| Symptoms | Decreased ability to exercise, palpitations, shortness of breath, leg swelling[2][3] |
| Complications | Liver failure, blood clots[2] |
| Causes | Amyloidosis, sarcoidosis, hemochromatosis, Loeffler endocarditis, storage diseases, diabetes, scleroderma, radiation therapy, certain medications, cancer[2] |
| Diagnostic method | Electrocardiogram (ECG), ultrasound of the heart, endomyocardial biopsy[2] |
| Differential diagnosis | Constrictive pericarditis, hypertensive heart disease, hypertrophic cardiomyopathy[2] |
| Treatment | Based on symptoms and the underlying cause[2] |
| Prognosis | Life expectancy 2 to 5 years[2] |
| Frequency | Rare[2] |
Restrictive cardiomyopathy (RCM) is a disease of heart muscle in which the ventricles do not appropriately relax and fill despite relatively normal contraction.[4][3] Symptoms may vary from a decreased ability to exercise, to new onset atrial fibrillation, to heart failure.[2] In some sudden cardiac arrest is the first indication of the disease.[2] Other complications may include liver failure and blood clots.[2]
The most common causes are amyloidosis, sarcoidosis, hemochromatosis, and Loeffler endocarditis.[2] Other causes include storage diseases, diabetes, scleroderma, radiation therapy, certain medications, and cancer.[2] Diagnosis may be supported by electrocardiogram (ECG), ultrasound of the heart, and endomyocardial biopsy.[2]
There is no cure.[2] Treatment involves addressing the underlying cause and measures to improve heart failure.[2] Heart failure may be treated with diuretics such as furosemide, calcium channel blockers, or beta blockers.[2] For sarcoidosis, antiarrhythmics and immunosuppressants are also commonly used.[2] Hemochromatosis may be treated with removal of blood.[2] In certain cases a heart transplant may be an option.[2]
Restrictive cardiomyopathy is relatively rare.[2] It represents about 5% of cardiomyopathy cases with the hypertrophic and dilated types being more common.[2] Life expectancy follow diagnosis is generally 2 to 5 years.[2] Cases of RCM were described in the the 1930s.[5] Cardiomyopathy; however, was not divided into its three main groups until 1961.[1]
Those with RCM will experience decreased exercise tolerance, fatigue, jugular venous distention, peripheral edema, and ascites.[6] Arrhythmias and conduction blocks are common.
RCM can be caused by genetic or non-genetic factors.[7][8][9] Thus causes can be divide into primary and secondary.[10] It can also be organized into infiltrative, storage diseases, non-infiltrative, and endomyocardial causes.[11] The most common cause of restrictive cardiomyopathy is amyloidosis.[6]
Rhythmicity and contractility of the heart may be normal, but the stiff walls of the heart chambers (atria and ventricles) keep them from adequately filling, reducing preload and end-diastolic volume. Thus, blood flow is reduced, and blood volume that would normally enter the heart is backed up in the circulatory system. In time, restrictive cardiomyopathy patients develop diastolic dysfunction and eventually heart failure.

Diagnosis is typically made via echocardiography. Patients will demonstrate normal systolic function, diastolic dysfunction, and a restrictive filling pattern.[11] 2-dimensional and Doppler studies are necessary to distinguish RCM from constrictive pericarditis. Cardiac MRI and transvenous endomyocardial biopsy may also be necessary in some cases.[6][11] Reduced QRS voltage on EKG may be an indicator of amyloidosis-induced restrictive cardiomyopathy.[11]
Untreated hearts with RCM often develop the following characteristics:[citation needed]
Treatment of restrictive cardiomyopathy should focus on management of causative conditions (for example, using corticosteroids if the cause is sarcoidosis), and slowing the progression of cardiomyopathy.[11] Salt-restriction, diuretics, angiotensin-converting enzyme inhibitors, and anticoagulation may be indicated for managing restrictive cardiomyopathy.[12]
Calcium channel blockers are generally contraindicated due to their negative inotropic effect, particularly in cardiomyopathy caused by amyloidosis.[13][14] Digoxin, calcium channel blocking drugs and beta-adrenergic blocking agents provide little benefit, except in the subgroup of restrictive cardiomyopathy with atrial fibrillation.[15] Vasodilators are also typically ineffective because systolic function is usually preserved in cases of RCM.[6]
Heart failure resulting from restrictive cardiomyopathy will usually eventually have to be treated by cardiac transplantation or left ventricular assist device.[12]
Endomyocardial fibrosis is generally limited to the tropics and sub-saharan Africa.[11] The highest incidence of death caused by cardiac sarcoidosis is found in Japan.[16]
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| Classification | |
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| External resources |
Categories: [Cardiomyopathy] [RTT]