How would you know when someone fakes a heart attack?

Heart attack: Yes, if the work up is entirely negative.

Time: Perceived symptoms are not like a real one no sweating, pallor, fear of death. Stable vital signs negative chemistry and ekg testing. Some may end up with cardiac stress testing, cardiac catheterization to prove negative. Some are mental health issues, others turn out to have other diseases that mimic and are not faking just confused.