Acquired left bundle branch block in an asymptomatic fighter pilot: a case report

This report describes a case of acquired left bundle branch block (LBBB) in an asymptomatic F/A-18 fighter pilot of the Royal Australian Air Force. The previously fit and healthy pilot was found to have LBBB on routine electrocardiographic screening prior to his annual aircrew medical. He was completely asymptomatic, and the only potential etiological factor was a short-lived acute gastrointestinal infectious illness some 4 mo previously. The pilot was extensively investigated with the full range of available diagnostic procedures, including coronary angiography and cardiac biopsy. No cause was determined for his LBBB pattern, and he was assessed as having normal cardiovascular function. The aeromedical disposition of this aviator and the issues involved in determining fitness to fly in such a case are discussed. The importance of thorough clinical investigation and appropriate follow-up are highlighted.