I'm pretty sure my heart attack four+ years ago was actually triggered by anaphylaxis due to reaction to a body wash I had been using. I was breaking out in a bad all-body rash after using that body wash for a couple of weeks but I thought it was the hotel bed sheets (detergent) that was my allergy and I was planning to check out of the hotel literally the day after when I had my heart attack. In the hospital my rash started getting better being unable to take showers and the rash started coming back when I got out of the hospital and taking showers again. Finally figured out it was the body wash... and realized that it might have gotten so bad it triggered the heart attack, since I otherwise before and after had no heart issues.
Long story short... was considering the possibility of taking a couple of showers a day using body wash that I'm allergic to and see if I could induce it on purpose. The heart attack I had was completely painless, I just passed out.