Pathfinder 1E Murder Variant Channeling question

[koesherbacon]

I have a question about channeling negative energy with the Murder variant channeling.
According to the variant channeling rules...

Murder: Heal—Creatures that critically hit before the end of your next turn add a bleed effect equal to your channel bonus. Harm—Creatures gain a bleed effect equal to your channel penalty.

Is that bleed effect only on critical hits? Or is it a regular bleed effect that remains until their healed?

Thanks