What should I order to find out if my child has heart disease?

[MNquestions]

about three years ago I believe my daughter suffered heart failure in an emergency room while suffering from pneumonia. Looking at her records there is no mention of heart disease anywhere. in the hospital they asked her if she wanted to know her diagnosis and she said no. When she goes in to the clinic they make no mention of it. I have been treating her with diet, exercise, and tutors since she had developed a delay in response after her illness. This has worked very well. My question is is it normal for doctors to do this kind of thing if that's what they did? I also need to figure out what to ask for in a workup. I assume an EKG at the very least. I am wondering if I need to go to a different clinic. About moving to a different clinic, I tried that and they declined to see her. I can keep trying though.