He was 44.
Duchesne collapsed and could not be resuscitated, she said. Reports said he apparently died of cardiac arrest, but the exact cause of death was not immediately known.
The native of Quebec was an eighth-round draft pick of the Washington Capitals in 1981 and made the NHL club out of his first training camp.
The six-foot, 190-pound forward went on to play 1,028 NHL games, scoring 179 goals and assisting on 254, and another 84 playoff games.
After six seasons with Washington, he was traded to the Quebec Nordiques along with forward Alan Haworth and a first-round draft pick - that turned out to be Joe Sakic - for Dale Hunter and goalie Clint Malarchuk.
Two years later, he moved on to Minnesota and was a member of the North Stars team that reached the Stanley Cup final in 1991.
He finished his NHL career with the San Jose Sharks and the Floirida Panthers, retiring after the 1994-95 season.
"We are extremely shocked and saddened by this news," Sharks GM Doug Wilson stated in a team news release. "Gaetan, in every way, epitomized what a team player should be - unselfish, caring and supportive of his teammates.
"His love for the game was unmeasured and despite his relatively short career in San Jose his connection with our fans was amongst the strongest of any player to ever wear our uniform. He was a remarkable man who will be deeply missed."
Duchesne later worked as an assistant coach with the defunct Quebec Rafales of the IHL and the Remparts of the Quebec Major Junior Hockey League.
He was out of hockey in recent years, running an architechtural supply business with his brother in the province's capital.
Duchesne is survived by his wife, a daughter and a son, Jeremy, who is a goaltender with the Val d'Or Foreurs of the QMJHL.