T.C.
The pediatrician heard a heart murmur with my son when he was 4 years old. Maybe they never heard it before because he could never be quiet enough. When we went to the cardiologist, they listened to his heart, and checked the electrical signals with an EKG. Then they spent about 45 minutes doing imaging of his heart(I forgot what it's actually called, but it was like a sonogram). That was the part that showed them the details of exactly what was wrong.
My son did turn out to need surgery for a hole in his heart, and a related problem with valve that didn't close all the way. It was an operation that the experienced surgeon did all the time, but it was like a week-long nightmare to me. After that, my son healed well, had so much more energy, and gained 4 pounds right away. We go back to the cardiologist every 2 years for a checkup, and we joined a support group for kids with heart defects.