Cardiomyopathy is any disease of the heart muscle, in which the heart loses its ability to pump blood and, in some instances, heart rhythm is disturbed, leading to irregular heartbeats, or arrhythmias. There may be multiple causes of cardiomyopathy, including viral infections. Sometimes, the exact cause of the muscle disease is never found.
How does cardiomyopathy differ from other heart disorders?
Cardiomyopathy differs from many of the other disorders of the heart in several ways, including:
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It is fairly uncommon, affecting only about 50,000 Americans.
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It is a leading cause for heart transplantation.
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It can, and often does, occur in the young.
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The condition tends to be progressive and sometimes worsens fairly quickly.
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Non-ischemic cardiomyopathy is due to specific causes, and is often associated with diseases involving other organs as well as the heart.
Three types of non-ischemic cardiomyopathy:
1. Hypertrophic cardiomyopathy (also known as hypertrophic obstructive cardiomyopathy, HOCM; asymmetric septal hypertrophy, ASH; or idiopathic hypertrophic subaortic stenosis, IHSS). In this type of cardiomyopathy, the muscle mass of the left ventricle of the heart is larger than normal, or the wall between the two ventricles (septum) becomes enlarged and obstructs the blood flow from the left ventricle. Because it prevents the heart from properly relaxing between beats, it fills with blood, which eventually limits the pumping action. A heart murmur may be heard.
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This is a rare disease and most cases are inherited.
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It can affect men and women of all ages, and symptoms can appear in childhood or adulthood.
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Symptoms include shortness of breath on exertion, dizziness, fainting, and angina pectoris.
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Some patients experience cardiac arrhythmias, which may lead to sudden death.
2. Dilated (congestive) cardiomyopathy. This is the most-frequent form of non-ischemic cardiomyopathy. The cavity of the heart is enlarged and stretched (cardiac dilation) causing the heart to become weak and not pump normally.
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This occurs most often in middle-aged people and more often in men than women, but has been diagnosed in people of all ages, including children.
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Most patients develop congestive heart failure.
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Dilated cardiomyopathy can be caused by chronic, excessive consumption of alcohol along with dietary deficiencies.
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It occasionally occurs as a complication of pregnancy and childbirth.
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Other suggested causes are: various infections, mostly viral, which lead to an inflammation of the heart muscle (myocarditis); toxins; and, rarely, heredity. Sometimes drugs used to treat a different medical condition can damage the heart and produce dilated cardiomyopathy. However, in most cases, a specific cause for the damage is never identified.
3. Restrictive cardiomyopathy. In this least-common type of cardiomyopathy in the US, the myocardium of the ventricles becomes excessively rigid, and the filling of the ventricles with blood between heart beats is impaired.
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It usually results from another disease, which occurs elsewhere in the body.
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Restrictive cardiomyopathy does not appear to be inherited, but some of the diseases that lead to the condition are genetically transmitted.
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Symptoms may include fatigue, swelling of the extremities, and difficulty breathing on exertion.
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