What are some of the signs that leads up to a person having a heart attack, especially in their sleep?

The "classic" signs and symptoms of AMI are chest pain or pressure, nausea/vomiting, diaphoresis (profuse sweating), and shortness of breath (SOB). Classic means that these S/S are very, very common and a vast number of people present with this clinical picture. However, by no means does this indicate that all AMI patients will display these S/S. Some people have no S/S at all, some have very vague presentations, some may complain of jaw pain or arm pain, some may be SOB but have no chest pain. Females commonly present with atypical S/S.

If someone had AMI while sleeping, some of them would wake up from the pain, assuming they had pain. Others would not wake up at all.