About eternal heart

[ComaNaRi]

I have only 1 healt(no other empty heart left) and I just find 1 eternal heart.
If I trade in devil room(Which require one heart) will Isaac die?
p.s. Sorry for my poor english

[Flavorable]

In short. Yes.

The eternal heart doesn't turn into a health up until the following floor, which means, for all intents and purposes, you only have 1 health, no more, no less.

[Nani]

The eternal heart is half a heart worth of life, You can see that when you give the devil beggar hearts, or the blood donation machine. I never was in your particular situation, since at that point I'd refuse any devil deal (except those that give me soul hearts, like the mark or the pact, the cloak or abbadon.

So in short: Don't risk it unless the item you can take gives you some more hearts. Also eternal hearts count as half a heart until you get to the next floor.

[The Renderer]

I also think you will die, but hey, try it out and tell us what happened!

[ComaNaRi]

Oh no... I made guppy set...

[Neo Kefka]

Originally posted by Nani:

The eternal heart is half a heart worth of life

Yes, but it isn't self sufficient. it needs a red heart container to count as health. A similar thing happens if you have only spirit hearts, the eternal heart won't count as health

[ComaNaRi]

Thank you for the information.
Anyway I died :(