One in 150 children enters the world with a heart defect. Sometimes, there’s no evidence of a problem until a seemingly healthy teen has unexplained shortness of breath or collapses on the sports field. Cardiomyopathy is a disease of the heart muscle in which the heart is enlarged and unable to pump properly. There are several forms of the disease, each with a variety of possible causes, symptoms and treatments. If your child has been diagnosed with cardiomyopathy, it is important to find a doctor who thoroughly understands the condition and has experience treating it in kids.