A doctor says simple good luck led to the discovery of a heart disease that could have threatened the life of Monty Williams had the 6-foot-7 former Potomac (Md.) High School All-Met gone on playing basketball for Notre Dame.

The diagnosis grew from an "extra heart sound" noticed Sept. 4 during a preseason physical examination on Williams, an Irish regular last season who had been set as a 1990-91 starter. "Sometimes it's there, sometimes it's not," university doctor Stephen Simons said. "It just happened to be there that night."

The disease, hypertrophic cardiomyopathy (abnormal thickening of heart muscle), has ended Williams's basketball career. "With that diagnosis, there is an undue and unacceptable risk of sudden death," the doctor said.

"I was very lucky to get a second chance," Williams said. "I wasn't on the court and died like Hank Gathers did."

Williams's disease is different from the sudden abnormal heart rhythm that killed Gathers at Loyola Marymount March 4. But Coach Digger Phelps said he conferred with the medical specialists, then told Williams his career was over.

"There is every reason to believe Monty will lead a normal life and a long life," Simons said.