[Transient right bundle branch block during anesthesia].

Transient right bundle branch block occasionally occurs under anesthesia. We report a case of heart rate dependent right bundle branch block during sevoflurane anesthesia. A 74-year-old man was scheduled for partial hepatectomy. Past medical history was unremarkable, and preoperative electrocardiogram showed no conduction abnormalities. Operation was performed with epidural and general anesthesia. Five hours after induction of general anesthesia, complete right bundle branch block (CRBBB) occurred gradually without any hemodynamic changes. Although CRBBB persisted in his electrocardiogram (ECG) during surgery, recovery to normal conduction was observed 8 hours after surgery. The 12-lead ECG after disappearance of CRBBB was normal. There was no change in his vital signs and subjective symptoms. Serum level of creatine phosphokinase (CPK) isoenzyme was within normal ranges, and change of ventricular conduction corresponded with the change of heart rate. These observations suggest that transient CRBBB in this case was rate dependent.