ok, to have a heart attack
...... VERY RARE....
) is to be more likely.
does it appear after have lunch? o after getting stressed?
anyway, the best thing you can do is to lower you weight and do exercises, maybe you want to be revised by a doctor so you can feel more comfortable about that.
also, the heart attack pain is different of what you feel, it is like being "hug" by something, like a constrictor pain, it's hard to explain because english is not my mother language.