Unusual complication of bifascicular block during surgery under general anesthesia.

This report describes the occurrence of Mobitz type II AV block during surgery under general anesthesia in a patient with apparently uncomplicated right bundle branch and left anterior fascicular block (RBBB and LAH). Although prophylactic pacing is not usually recommended in uncomplicated RBBB and LAH, the events in this case suggest that this abnormality may not always be benign during surgery. Continuous monitoring is essential and emergency equipment for temporary pacing should be readily available near the operating and recovery rooms.