William J. Fitz-Patrick jr., 64, who retired in 1976 as records management officer for the Department of Commerce Maritime Administration, died Tuesday at his Annandale home after a heart attack.

Mr. Fitz-Patrick moved to the Washington area in 1966 and became records management officer for the Maritime Administration the following year.

A former health-care supply specialist, he previously had worked in that field for the Veterans Administration in Massachusetts and for the U.S. Public Health Service in New York and California. He also had been a consultant to Cornell University and a hospital supply consultant for Chicago hospitals.

Born in Chelsea, Mass., Mrs. Fitz-Patrick attended Burdette College in Massachusetts and Boston University.

A cheif quartermaster in the Navy during World War II, he had participated in minesweeping operations for the historic Yalta Conference toward the end of the war.

Survivors include his wife, Josephine Krok Fitz-Patrick of Annandale, a retired captain in the U.S. Public Health Service, his mother, Florence Fitz-Patrick, and a sister, Florence Baker, both of Branford,Conn.

The family suggests that expressions of sympathy be in the form of contributions to the Humane Society of Fairfax County Inc. in Falls Church.