My son is 8. He had a small hole in his heart when he was a baby. It healed itself. He plays alot of sports, and somettimes his heart beats real fast, even when hes just sitting, or laying down doing nothing. Im worried that while he is playing sports something could happen. should i have him tested with a ecg, or something else? My daughters does the same. She is 16, and is a dancer. At her physical this year, the dr questioned her about her heart. Should i be concerned?