From the American Heart Association
Cardiomyopathy refers to a diseased state of the heart involving abnormalities of the muscle fibers, which contract with each heartbeat. It can be considered “primary” or “secondary”:
In primary cases, cardiomyopathy occurs because the muscle cells themselves are abnormal (usually due to a gene mutation).
Secondary cases of cardiomyopathy involve healthy heart muscle cells that are adversely affected by other conditions. Precipitating conditions include low blood flow to the heart, low blood oxygen, high blood pressure and certain infections.
According to the Pediatric Cardiomyopathy Registry, one in every 100,000 children in the U.S. under the age of 18 is diagnosed with cardiomyopathy. The majority of diagnosed children are under 12 months, followed by children 12 to 18 years old.
Cardiomyopathies can be grouped into four broad categories. The clinical features and treatment options differ for each.
Miscellaneous cardiomyopathies (rare)