There's two versions of Fast Healing, but They're same which triggers every a min.
Fast Healing(Epic Destiny): You heal [2/4/6]d20 HP each minute using positive energy.
Fast Healing(Epic TR): You heal "5 plus 5 per 5 character level" HP each minute. This stacks up 3 times.
I can't understand why devs set the cycle as a min. I'm not sure why this is Fast healing. the name of current version should be said as Slight Moment of Great Healing, not FAST. even fey spring(Shiradi ED) can be said as fast healing - It heals 1d100 per 60/45/30 seconds.
I suggest that Fast Healings should be every [60/40/20] seconds per rank(or stack), not every a min.