system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Since Magneto has been shown to be able to control blood via the iron content, could be manually circulate his own blood if his heart stopped working until he received medical attention?

In a comic in the 90s, I believe it was the Magneto limited series, Mags is shown killing a bunch of soldiers sent to kill him by manipulating their blood. So could he provide himself with artificial circulation?

I guess we can have a twofer here and ask the same question about bloodbenders in the Avatar universe.
gpt
Magneto: probably. He once survived his own death as pure energy by maintaining the nerve impulses using his power without any body.

Bloodbenders: usually benders need to move to bend, but if you're really good - and you have to be good to be a bloodbender - you can do it without moving. Bloodbenders have been shown canceling out the effect of bloodbending on their bodies, so they can clearly effect themselves. They should be able to resist a heart attack no problem if they realize what's happening.