One thing that causes intense chest pain mimicking heart attack like symtoms is esophogeal spasm.... it hurts like heck - can last for hours - and I ended up in urgent care once with those symtoms to rule out heart problems... they were able to do that and it it turned out it was "just" my esophogeous kinda tied in a knot...... was ok the next day and I get flare ups occasionally but at least I know what I'm dealing with...
Hope its nothing major there! (I do have heart rythm problems I take meds for - but they dont cause pain)