JERUSALEM, June 8 (JTA) — Israeli doctors have performed their first implant of an artificial heart. The patient, a 50-year-old man, was listed in critical condition after the operation was performed this week at Sheba Hospital in Tel Hashomer. Dr. Ya’acov Lavi, director of the transplant department at the hospital and head of the surgery team, said the operation took eight hours. An artificial heart generally serves as a temporary measure until an appropriate donor is found. The patient, who has a rare blood type, was urgently in need of a transplant. He was hospitalized over a week ago in critical condition. When no appropriate donor was found after eight days, doctors decided he should undergo an artificial heart implant until a natural organ was found.