A memorabilia dealer who blames his heart attacks on the stress of being robbed at gunpoint by O.J. Simpson is suing the former football star and five other men who were in the room during the heist, seeking unspecified civil damages.

A lawyer for Bruce Fromong said Monday he intends show a Nevada jury that his 55-year-old client's four heart attacks were caused by the emotional stress of the September 2007 robbery in a Las Vegas casino hotel room and its aftermath.

"We think we can prove the causal connection," said Fromong's attorney, Elliot Blut of Century City, Calif. Blut also practices law in Nevada.

Fromong, of North Las Vegas, said he is still seeing doctors for physical maladies he blames on the encounter. He said he and his wife, Lynette Fromong, have suffered financially, mentally and physically.

"This has affected our entire life," Fromong said.

Simpson's lawyer, Yale Galanter, called the lawsuit frivolous.

"I'm going to fight this guy tooth and nail," Galanter said from Miami, Fla. "Initially, Fromong said his heart attacks were caused by the news media. Now he's switching his story and saying O.J. caused it."

Clark County District Court Judge Jessie Walsh did not immediately set a hearing on the lawsuit filed Friday in Las Vegas.

It names Simpson and convicted co-defendant Clarence "C.J." Stewart as defendants, along with four former co-defendants who were initially charged with Simpson and Stewart but took plea deals and testified for the prosecution. Walter Alexander, Charles Cashmore, Charles Ehrlich and Michael McClinton each pleaded guilty to lesser felonies and received probation.

The lawsuit also names Thomas Riccio — the go-between who arranged the ill-fated meeting with Fromong and was never charged with a crime.

Alexander's lawyer in the Simpson case, Robert Dennis Rentzer of Tarzana, Calif., said he no longer represents Alexander. Riccio and lawyers for Cashmore, Ehrlich and McClinton did not immediately respond to messages seeking comment.

The other memorabilia peddler who was robbed, Alfred Beardsley, is not named as a defendant.

"I wasn't going to sue another victim," Fromong said.

Stewart's lawyer, Brent Bryson, said Fromong testified at trial that he wasn't scared by Stewart and that Fromong recalled someone he thought was Stewart patting him down for weapons during the Sept. 13, 2007, confrontation at the Palace Station casino-hotel.

"He said it was the men with the guns he was afraid of," Bryson said.

Simpson, 62, is serving nine to 33 years at Lovelock Correctional Center, 90 miles northeast of Reno, for his conviction on charges including armed robbery and kidnapping.

Simpson claimed he didn't know anyone had guns and that he was only trying to retrieve items that had been stolen after his acquittal in the 1994 slayings of his ex-wife, Nicole Brown Simpson, and her friend, Ron Goldman, in Los Angeles.

Stewart, 55, is serving 7 1/2 to 27 years at Northern Nevada Correctional Center in Carson City.

Both men are appealing their convictions.