Broken Heart is an unlockable pickup in Repentance Plus, a mod for The Binding of Isaac.
Broken Hearts are stored in a separate slot below Isaac's actual health bar.
If Isaac possesses at least one Broken heart, he is able to reroll any item into another item from the current room's pool at the cost of gaining one actual Broken heart.
This can be done by standing very near the desired item for long enough and waiting for the bar underneath the item to fill.
Has a 0.8% chance to replace a Heart.
Unlock Tainted Isaac.