SAN DIEGO (AP) _ Dr. Walter Robert Tkach, a former White House physician who served three presidents, has died of heart disease. He was 72.

The retired Air Force major general, who flew into combat zones during the Vietnam War to aid the wounded, died Nov. 1 at his Scripps Ranch home.

Tkach was an assistant White House physician during the eight years of the Eisenhower administration and the first eight months of the Kennedy administration. He was senior White House doctor during Richard Nixon's years in office.

Retired Army Brig. Gen. Chester Ward, who was an assistant White House physician under Tkach, described him as ''a very caring, compassionate individual.''

''He taught me and the other people around him an awful lot about medicine, medical ethics within our political system,'' Ward said. ''His professional competence and his ethical integrity were without peer.''

The LaBelle, Pa., native earned his medical degree from the University of Pittsburgh in 1945, then joined the Army.

During the U.S. occupation of Japan, Tkach ran the medical dispensary at Gen. Douglas MacArthur's headquarters in Tokyo.

He transferred to the Air Force in 1949, received training in aerospace and aviation medicine, and spent the Korean War years as a base flght surgeon at Sewart Air Force Base, Tenn.

Tkach began his White House service in 1952. Eight months into President Kennedy's administration, he left the White House for Hickam Air Force Base in Hawaii, where he was deputy surgeon of Pacific Air Forces.

He then became command surgeon of the 7th Air Force at what was then Tan Son Nhut Air Base in South Vietnam. Tkach often flew directly to combat areas to help treat the wounded.

With Nixon's election in 1968, Tkach returned to the White House as the president's physician. After Nixon's resignation six years later, Tkach became command surgeon for the Air Force Systems Command at Andrews Air Force Base.

In 1979, Tkach retired and moved to San Diego.

He is survived by his wife, Cheryle, and sons Marc, Jonathan and John Robert.

Tkach was to be buried with full military honors next Tuesday at Arlington National Cemetary, relatives said.