RESTRICTIVE CARDIOMYOPATHYRESTRICTIVE CARDIOMYOPATHY
A. DEFINITION
C. SYMPTOMS
E. TREATMENTS
This third type of cardiomyopathy is characterized by restrictive filling and reduced diastolic volume of the left or both ventricles with normal or near normal systolic function and wall thickness. The heart pictured is from a patient with restrictive cardiomyopathy due to amyloidosis.
Restrictive Cardiomyopathy (RCM) is a group of disorders of the heart muscle, in which the heart chambers are unable to fill properly and cannot pump blood efficiently. The decreased heart function will affect the lungs, liver, and other body systems. The myocardium becomes excessively rigid and the filling of the ventricles with blood between heart beats is impaired. This is the least common type of cardiomyopathy.
RCM is otherwise known as infiltrative cardiomyopathy. It affects approximately 1 out of 1000 people. The most frequent causes are amyloidosis, radiation to the chest, and fibrosis (scarring) after open heart surgery. Loeffler's syndrome causes fibrosis of the lining of the heart. Sarcoidosis, hemochromatosis, carcinoid syndrome, and connective tissue diseases such as scleroderma may also cause a restrictive type of cardiomyopathy.
Symptoms of RCM include excessive tiredness (fatigue), swelling of the abdomen, swelling of the feet and ankles, cough, difficulty breathing especially with exertion, difficulty breathing at night when lying flat, and easy fatigue (poor tolerance of exercise).
A physical examination for RCM may show signs of heart failure with fluid backup into the lungs or the systemic circulation (the extremities, gastrointestinal tract, and liver). The patient's neck veins may be distended. Listening to the chest with a stethoscope (auscultation) may show lung crackles and abnormal or distant heart sounds.
Procedures used in order to indicate restrictive cardiomyopathy (by showing symmetrical thickened ventricle walls, decreased cardiac output, and/or elevated end diastolic pressure) include: an ECG (electrocardiogram) described on the HCM page, an echocardiogram, a coronary, angiography, a chest X-ray, a chest CT scan, a chest MRI scan.
Unfortunately, restrictive cardiomyopathy may be hard to differentiate from constrictive pericarditis. A biopsy of the heart muscle may be used to confirm the diagnosis. In some cases, surgical exploration is the only means to definitely distinguish restrictive cardiomyopathy from constrictive pericarditis. Sometimes, distinction of RCM may come post mortum.
Little therapy is known to be effective for the treatment of restrictive cardiomyopathy. The goal of treatment, like in other cardiomyopathies, is to control symptoms in order to improve the quality of life.
Various medications may be used to control symptoms. Diuretics may help somewhat in removing fluid, which can improve breathing, but excessive use can worsen symptoms. A heart transplant may be considered if the function of the heart is very poor.
The probable outcome of restrictive cardiomyopathy patients is poor. Ttreatments are not usually very effective. People with restrictive cardiomyopathy may be candidates for heart transplant. Complications such as lethal arrhythmias and progressive heart failure are outcomes of those patients with RCM.
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