Lydia Butler's heart problems were so severe that she had three open-heart surgeries by the time she was 4 years old. Today, doctors are not only keeping an eye on the 7-year-old's heart. They also are trying to figure out what is going on inside her brain.

Lydia has a diagnosis of developmental coordination disorder and attention deficit hyperactivity disorder (ADHD). Researchers at Cincinnati Children's say she is an example of how congenital heart disease and developmental disorders such as ADHD are linked.