[DCWildcat]

In behaviorist terms, it should look like this, basic classical conditioning:

"Poker context":Sharp money risk-> Increased heart rate
"Poker context" -> Increased heart rate

Where "Poker context" is an neutral stimulus (nothing about an all-in moment intrinsically makes you physiologically distressed), sharp money risk (for lack of a better term) is an unconditioned stimulus (not really, but for our purposes) for an unconditioned response (heart rate). This leads to poker context becomming a conditioned stimulus for the conditioned response of increased heart rate.

You're extinguishing it by playing with money you don't care about, so
"Poker context" -> no response
becomes the norm.

Again, you'll never entirely eliminate it, but you can probably lower it.