tiredness after chest pain

I have a really stupid question.  My 4 year old son has a heart history and he will complain of heart palpatationa. wich his HR is extremely high. then there are times that he complains that his HEART HURTS and he will grab at his chest on the left side(just to the left of his surgical scar. for example his last one he said that his heart hurt and described how it felt. we and the doctors don't know what to think of it it lasts only 20 minutes,however every time he has these chest pains, he is very tired and sleeps a good part of the day. is this normal with "real" chest pains. since we aren't sure if it is a muscle spasm, heart burn that is going on or if it really is chest pain.
I can' t wait until the 5th of June hopefully we will get answers on everything
michelle