Edward F. (Ned) Ryan, 55, who was manager of advertising, promotion and public relations for NBC in Washington for 15 years, died Sunday following a heart attack.

Mr. Rayan who had worn a pace-maker since October, 1975, was stricken while helping move his son, Terrence, 16, to an ambulance. The son had a compound ankle fracture and was being taken to Montgomery General hospital. The Ryans live in Silver Spring.

Mr. Ryan was a native of Syracuse and a graduate of the Central City Business Institute and Syracuse University. He also served in the U.S. Marine Corps for two years and also served in the Air Transport Command during World War II.

He entered broadcasting in Syracuse and was promotion manager at WHEN-TV for four years. He had similar titles at stations in Boston, East Lansing, Mich, and Huntington, W. Va.

Mr. Ryan worked for the CBS Television Network in New York for four years and spent two years with the Dowd, Redfield and Johnstone advertising agency in New York. He came to NBC, Washington, in 1961.

A cheerful, estrovert with a deep interest in community affairs, Mr. Ryan was on the board of directors of the D.C. Lung Association and the Metropolitan Washington Coalition for Clean Air. He was a member of the National Press Club, the Metropolitan Washington Board of Trade, the Advertising Club, the National Academy of Television Arts and Sciences and the Broadcasters Promotion Association.

He suffered his first heart attack shortly after resigning from NBC in 1975. After the pacemaker was installed Mr. Ryan did free lance work for the Public Broadcasting Service and the Foster Children's Plan.

He is survived by his wife, the former Elizabeth Evans and their six children: Mary Elizabeth Wessling of Olney, Md., Edward F. Ryan Jr., Patricia Catherine, Daniel J., Elizabeth Ann and Terrence Patrick of the home; two grandchildren; a sister, Mrs. Charles F. McAllister and a brother, Joseph E. Ryan, both of Syracuse.