Helen M. Tomascik, 63, a top aide to Rep. Daniel J. Flood (D-Pa.) for 25 years before his retirement last month, died of cardiac arrest Monday at her family's home in Wilkes-Barre, Pa., where she was convalescing from a heart aliment.

Miss Tomascik joined Flood's congressional staff in 1955 as a secretary and later became his executive secretary. She was named his administrative assistant in 1976.

She had specialized in handling benefit claims for black lung victims under the 1969 Coal Mine Health and Safety Act, which Flood cosponsored, and served as a caseworker on military and immigration matters.

A native of Wilkes-Barre, Miss Tomascik graduated from the Wharton School of Finance at the University of Pennsylvania.

During World War II, she was an assistant to Peter Margie, then the owner of the Wilkes-Barre Barons, a Class A farm team for the Cleveland Indians baseball team. She became the team's general manager in 1950, a position she held for five years before coming to Washington.

Miss Tomascik lived in Washington and attended the Shrine of the Most Blessed Sacrament Catholic Church here.

She was a founding member and former officer of the Junior Catholic Daughters of America, a former officer of Quota International and a member of the Congressional Staff Club.

Survivors include two sisters, Margaret and Marion, and a brother, Matthew, all of Wilkes-Barre.