Suffered Commotio Cordis On Ice In '98

Chris Pronger is one of the greatest hockey defenders ever, but perhaps he's more known for his own terrifying in-game medical emergency ... the former NHL MVP suffered commotio cordis after taking a slapshot to the heart during a playoff game in 1998.

TMZ Sports talked to the retired 48-year-old NHL great about the parallels between him and Damar Hamlin ... as many physicians have theorized the 24-year-old Bills safety also experienced the extremely rare heart issue.

"I got hit with a slapshot literally right in the heart and in between beats and that's called commotio cordis where you get hit in between beats. Your heart thinks it beat so it skips one beat. Sometimes the heart restarts,…