It was a movie I saw on an Edmonton station I believe, probably around 2001. It was about a group of doctors that took turns stopping eachothers hearts, then would bring themselves back. Eventually they wanted to see how long they could stay out, and kept going longer and longer. That's all I can remember.

Was it sleepers?

This kind of fits the description, other than the date...

Flatliners (1990)

Flatliners is the name of the movie. They weren't doctors though, they were medical students. Starred: Kevin Bacon, Julia Roberts, Keifer Sutherland, William Baldwin and Oliver Platt. Awsome movie. Love it myself.