You can use a Flow-If<Health> conditional on updating to determine the amount of health/max health and then use that to call an Actor-Draw-SwitchToFrameXForSelf. You could do this for either When Update or When Draw, I'm not sure if it matters, though When Draw may produce better results.
It'll look something like the attached photo.
Note that I haven't tested this myself, but I've done similar so I'm sure it'll work unless there's an error. If you're not on the appropriate animation, however, this won't work, but you sound like you have one animation with multiple frames for each thing of health.