Rotten Heart is an unlockable pickup in The Binding of Isaac, added in the Repentance DLC.
Fills a whole red heart container, causing it to be depleted in just 1 hit.
Each rotten heart spawns 2 Blue Flies upon clearing a room.
Cannot be picked up by characters that cannot have red health.
This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this pickup for the previous Repentance version, check this page instead.
Enter the Corpse for the first time.