An Odd Thought

You know how people in movies sometimes inject themselves in the heart in life-or-death situation with something or the other that keeps them alive when nothing else will?
I don't think I could ever do that.
Why?
Because I don't know exactly where my heart lies. Sure, it's somewhere under my left boobage, but where?
When women pledge allegiance, we put our hands clear up by our necks. Men pledge with their hand near their waist.
So where the heck is my heart? Where would I inject that whatever it is that will save my life?
I hope to never be in a situation where I think, "Gee, maybe I should have figured that out. Now I'm gonna die because it appears I just injected that thing into my spleen." Or whatever.