Answer:
Sorry I Dont Know The Answer
I think in this situation you should first call 911 if you yourself are not trained in the medical field, then don't try to be. Because you could easily make things worse.
Greetings!
The heart consists of exactly 3 layers:
The Epicardium (external layer)
The Myocardium (middle layer)
The Endocardium (inside layer)
Hope this helps!
~Autumly
The answer is in the picture