SPN Question!

Does Castiel have a heartbeat?

Can he feel it beat underneath his ribs?

If something happened and they took him to a hospital, would the doctors be all "wtf?"

I guess the connected question is, does he breath?

I'm really just curious. I've written about Castiel being breathless enough to be like, "Whatever. My fic, my rules." But I'm working on a thing now and had something heart-related came up and am now curious about what y'all think.