Unless you already have some sort of heart problems/disease/whatever, it's almost impossible to consciously trigger a heart attack. The average healthy person is very unlikely to get a heart attack, in most circumstances. Of course, there's some factors that would make someone more likely to get one such as stress, obesity, blood pressure problems, smoking, etc. A heart attack occurs when blood flow gets blocked towards the heart, and I'm no doctor, but I'm 99% sure you can't consciously block an artery from flowing blood into your heart. You could smoke a hundred cigarettes and drink 15 cups of coffee - and still not get one. Not realistic, sorry to disappoint. That being said, I won't deny the fact that I'd considered this too at some point lol