Recurrent loss of consciousness in an aircrew member--a controllable cause.

A healthy 38-year-old technician aircrewman gave a 3-month history of recurrent loss of consciousness. Treatment for presumptive post-traumatic epilepsy was unsuccessful. Repeated cardiac investigation was negative until an episode of unconsciousness while instrumentated with a "Cardio-memo" recorder showed that an attack was accompanied by cardiac asystole. Further (invasive) cardiac investigations including electrophysiological studies were normal. Insertion of a dual chamber pacemaker (mode DDD) prevented any further attacks over a period of 4 years' observation. He was found fit to resume restricted flying duties and has experienced no problems in the air or elsewhere.