Dr. Leonard L. Bailey, who elicited both admiration and outrage by transplanting the heart of a baboon into a dying infant in 1984, died on May 12 at his home in Redlands, Calif. He was 76.

The cause was neck and throat cancer, his son Brooks said.

Although Dr. Bailey went on to pioneer human heart transplants for infants, and to build a renowned center for children’s cardiac surgery at Loma Linda University in Southern California, he remained best known to the public as the doctor behind the wrenching story of the infant known as Baby Fae.

Called Baby Fae at the time to protect her privacy, she was later identified as Stephanie Fae Beauclair. She was born in Barstow, Calif., on Oct. 14, 1984, with little more than half a heart. She had a fatal birth defect called hypoplastic left heart syndrome, in which the main pumping chamber of the heart does not develop. She was quickly transferred to Loma Linda.

At the time, babies with the condition lived only a few weeks, if that long. Surgery to try to repair the defect had poor results. Two infant heart transplants involving other patients had been tried at other hospitals, and failed. Donor hearts were vanishingly rare. A doctor told Stephanie’s mother, Teresa Beauclair, that she could keep her daughter in the hospital until the end, or take her home to die.