Hello! I Have A Quick Question And I’m Sorry If

Hello! I have a quick question and i’m Sorry if this is not the place to be asking. I dont want to waste anyone’s time so let me know. I am writing a novel about a teenager with a heart problem and I was wondering what different defects or diseases are common in teens with their hearts. I want to be as accurate as possible and I am looking for what its like to live with it and what needs to be done to help fix it.