When Isaac completes all of a floor's normal rooms, he will gain two red heart containers. When Isaac begins to move to the next floor, he will lose a red heart container. The effect cannot take away any blue or black hearts, so if Isaac has no red heart containers, the effect will not occur. If Isaac gains a red heart container by an eternal heart, this red heart container will not be deleted, as the effect of the item will occur before the eternal heart becomes a red heart container.
'Heart failure.'
When Isaac completes all of a floor's normal rooms, he will gain two red heart containers. When Isaac begins to move to the next floor, he will lose a red heart container. The effect cannot take away any blue or black hearts, so if Isaac has no red heart containers, the effect will not occur. If Isaac gains a red heart container by an eternal heart, this red heart container will not be deleted, as the effect of the item will occur before the eternal heart becomes a red heart container.