So, what ep is Valiente heart? the 5th ep?

Depends on if tu count Broken as one o 2 eps. I believe TPTB officially counts it as 2. So Braveheart will be 6th.

According to zorro, fox and the House producers, Broken counts as 2 episodes, so it goes like this:

1 & 2: Broken
3: Epic Fail
4: The Tyrant
5: Instant Karma
6: Valiente Heart

Valiente corazón will be the 6th episode.