I see absolutely no value in registering Pit Bulls. It’s just like registering guns - you don’t need the registry to know there was a problem after the fact. Also, and unusually for the Pit Bull, I don’t blame the dog for this. Heart attacks are painful and can look painful, and and CPR looks like a physical attack. This is just an unfortunate event.
You don’t do CPR unless the patient is in no pain - i.e. unresponsive, pulseless, dead as far as you can tell.
Of course the dog can’t figure that out. Sad story.