Out of just plain intrest and curiousity, I have a heart attack question...?

NO, I DONT THINK THAT I HAVE HAD ONE!!!!! I just have an unusual intrest in health care ( i plan on being a nurse). I know that sometimes, Myocardial Infarctions (heart attacks) can happen without any symptoms, but in my CPR cl, the symtoms sounded like they would take a toll on the body, pain-wise. so, if u do have a heart attack in ur sleep, wouldnt u wake up when u started to loose blood and have chest pressure. like in sleep apnea, when ur brain starts loosing oxygen, u wake up. so, is it the same with heart attacks? just curious