Any disease of the heart muscle that weakens the force of cardiac contractions, thereby reducing the efficiency of blood circulation. Cardiomyopathies may have an infectious, metabolic, nutritional, toxic, autoimmune, or degenerative cause. However, in many cases the cause is unknown.
There are 3 main types. In hypertrophic cardiomyopathy, which is usually inherited, the heart muscle is abnormally thickened. In dilated cardiomyopathy, metabolism of the heart muscle cells is abnormal and the walls of the heart tend to balloon out under pressure. Restrictive cardiomyopathy is caused by scarring of the endocardium (the inner lining of the heart) or by amyloidosis.
Symptoms of cardiomyopathy include fatigue, chest pain, and palpitations. The condition may lead to heart failure, symptoms of which include breathing difficulty and oedema. A chest X-ray may show enlargement of the heart, and echocardiography may show thickened heart muscle. A biopsy of heart muscle may reveal muscle cell abnormalities.
Symptoms may be treated with diuretic drugs to control heart failure and antiarrhythmic drugs to correct abnormal heart rhythm. In many cases, heart muscle function deteriorates, and the only remaining option is a heart transplant.
A general term covering primary disease of the heart muscle. (See HEART, DISEASES OF.)
n. any chronic disorder affecting the muscle of the heart. It may be inherited but can be caused by various conditions, including virus infections, alcohol abuse, beriberi (vitamin B1 deficiency), and amyloidosis. The cause is often unknown. It may result in enlargement of the heart, *heart failure, *arrhythmias, and *thromboembolism. Modern drug treatment improves symptoms and prognosis. See also hypertrophic cardiomyopathy.
a familial condition affecting the heart, characterized by unexplained thickening (hypertrophy) of the wall of the left ventricle. In many cases this is an incidental finding and patients have a good outcome. However, more severely affected patients may suffer chest pain, tachyarrhythmia (see arrhythmia), heart failure, and sudden death. In some cases there is focal thickening of muscle around the left ventricular outflow tract (asymmetric septal hypertrophy, ASH), and this can result in restriction of blood flow to the body (hypertrophic obstructive cardiomyopathy, HOCM). The diagnosis is made by electrocardiography, echocardiography, and cardiac *magnetic resonance imaging. Usually drug treatment is sufficient to control symptoms, but some patients require cardiac *catheterization or surgical treatment. Those deemed at highest risk of sudden death may require an *implantable cardiovertor defibrillator.... hypertrophic cardiomyopathy
a rare complication of pregnancy, occurring from the sixth month of pregnancy until six months postnatally (usually within six weeks of delivery). It can follow pre-eclampsia. It is characterized by palpitations, dyspnoea, oedema (peripheral and central), and impaired exercise tolerance. The diagnosis is confirmed on echocardiography. It has a high mortality and morbidity. Treatment of heart failure, anticoagulation, and in some cases immunosuppressant therapy is required; in some cases heart transplantation may be considered.... puerperal cardiomyopathy
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