What Causes Shortness Of Breath With Chest Pain And Fainting Spells?

My 22year old daughter has been fainting. We have seen drs who say she is stressed or dehydrated etc. She says before she faints her hands feel tingly and her arms seem unattatched from her body. She doesnt get short of breath or have any chest pain. Her blood sugar is normal. We cant find a trigger. Last time she fainted was in the shower and she really banged herself up. She has had bloodwork and a couple CT of her head. All normal. Could it be something with her heart? I have a friend who had a whole in her heart and fainted all the time. One dr mentioned a tilt table but another said her bp is fine. Any suggestions would be appreciated.