I'm also on the way of ending my life by triggering heart attack or failure. There has been example before such that even physically healthy human being can die due to heart failure under certain circumstances e.g. staying up and doing extreme sports at midnight - refer to the story of Godfrey Gao (my avatar). The plan I'm going to take is: 1.Starving for a few days (e.g. a week), 2.Keep smoking a lot during the time (as I found that smoking when hungry might cause inhaling of CO and feeling dizzy in head, and medical documents have said that smoking can promote the possibility of sudden dealth), 3.Not sleeping much during the time (at most 70% of normal time), 4.After all the previous steps, forcing myself to do extreme sports at midnight. I'm not sure if these steps can end myself by triggering heart failure, but I once tried starving for 3 days (during the Dragon Boat Festival) -> ate breakfast -> then did some strenuous exercises, and I found myself feeling quite dizzy and about to faint - even though I had some breakfast after starvation - so I stopped. I could imagine if the exercises were even more strenuous and I just kept doing them, then I might die suddenly.