Amy Louise Sloyan, 15, a lifelong resident of Northern Virginia and a student at Notre Dame Academy in Middleburg, Va., died Saturday at Loudoun Memorial Hospital in Leesburg, Va., following an apparent heart attack.

She was stricken at her home at Paeonian Springs, Va. An autopsy was planned.

Miss Sloyan, who was born in Washington, recently completed her freshman year at Notre Dame Academy, where she became a student last year. Earlier, she had attended Waterford Elementary, Loudoun Country Day and Blue Ridge Middle schools.

She was active in Riding for the Handicapped, a program for crippled or retarded people. She rode horse back herself, enjoyed swimming and played the piano.

She was the daughter of Patrick J. and Phyllis H. Sloyan. Her father is the White House correspondent of Newday (L.I.) newspaper.

In addition to her parents, of the home in Paeonian Springs, survivors include a sister, Nora, and two brothers, Patrick and John David, all of the home, and three grandparents, Dr. and Mrs. Louis Hampton, of Hanover, Pa., and Anna Mae Sloyan, of Albany, N.Y.

The family suggests that expressions of sympathy be in the form of contributions to Notre Dame Academy, to the Hamilton, Va., Volunteer Rescue Squad, or to the Leesburg Chapter of the American Heart Association for the purchase of cardio-pulmonary resuscitation equipment.