Sense of "Impending DOOM"!

In my pathophysiology class yesterday we were covering defects of the heart. When we began to talk about the topic of heart attacks, my teacher mentioned that most people who are at the early stage of a heart attack will experience a crushing feeling in their chest, and a sense of "impending doom". This is strange to me because I am sure I was not having a heart attack on Monday after my patho class, but as soon as my teacher began to hand back our exams from last week, that I wrote about most likely failing, I began to get a crushing feeling in my chest, and a feeling of "impending doom", it's amazing how a simple thing like getting back an exam can cause one to feel symptoms of a heart attack. Well anyways, I am happy to report that I did not in fact fail my first exam ever, I passed, I didn't ace it by any means but I passed, and I passed with a nice little cushion of a grade so in case I don't do so hot on the next exam, I have some leeway with my grade. Phew.....*sigh*...crushing chest pain subsiding....feeling of "impending doom" fading, until the next exam that is!