Fountain of Knowledge

So if I read the concept right, in your example, the sound of the front door easing open is the motivation.

Her visceral reaction is that her heart starts racing. That's the reaction she can't control.

Her reflex is that she bolted upright. That's the action she takes based on the visceral reaction. She's startled/scared (her heart is beating) and that puts her at attention (she sits up).

Listening is what she forces herself to do, so that's her rational reaction.

So in your example, your second sentence does follow the explanation.

I see what you're saying about the former sentence reading more smoothly, but thinking about it, she wouldn't bolt up before her heart started hammering.

So if you're being technical and listing things in the order they happened, the latter of your examples make more sense.

The thing is, you're also story telling. So sentence structure has to convey what you want your reader to focus on at the same time. Technical rule aren't always the best way to go.

So if "bolting up, heart hammering" draws more attention to what's important - in this case an overall fear and immediacy rather than a series of individual steps that need to be thought through, then it may be more appropriate to the story...

if that all makes sense