If you listen this word in “Vishnu sahasra namam” and are confused, here is my explanation…
Vysampayana has no business directly in “Vishnu sahasra namam”; which is part of “Mahabharatam”
He is a Third person(viewpoint) narrator. (to Janamejaya)
So, the original vyasa “Mahabharatam” will NEVER have “Vysampayana”. (Because it was before him..)
Also the name “Maha bharata” was coined by Vysampayana and not Vyasa..
Vyasa wrote “Jaya” and Vysampayana expanded it into the current day Maha bharata. So, its an expanded version..
The original Vyasa bharatam is a good read. Give a try.. has less about Krishna..