OK. Here's what I've done. I gave the heart to the ghost. Find the way myself out. Got out of the catacombs. Then read the thread. Turned back. Open the hidden stairs. Got the chests. But the entrance closed again.
I can not go out. The only thing showing a hand is a portrait downstairs. But when u click it nothing happens.
Beware : Do not enter the catacombs twice.