General anesthesia for a patient with asymptomatic sick sinus syndrome

A 67-year-old man with glioblastoma was scheduled for craniotomy. Before anesthesia induction, asymptomatic bradycardia (40 beats x min(-1)) occurred, and was resistant to atropine 0.4 mg. The surgery was postponed. He was diagnosed as sick sinus syndrome (sinus arrest). He received implantation of a temporary cardiac pacemaker on the day before the rescheduled surgery. Anesthesia was induced with thiopental 400 mg, fentanyl 200 microg, vecuronium 10 mg and isoflurane 5%, and maintained with isoflurane 1-2% in oxygen 3 l x min(-1) and air 3 l x min(-1). Pacing mode was set to fixed rate asynchronous pacing in the ventricle with a rate of 50 beats x min(-1) after anesthesia induction. Surgery was completed in 8 hours and 45 minutes without any complications. The pacing wire was removed the next day. For patients with sick sinus syndrome, implantation of the pacemaker is indicated in case of bradycardia-tachycardia syndrome or with any clinical symptoms. However, a pacemaker should be implanted before general anesthesia even in a patient with no clinical symptoms because of cardiovascular instability induced by anesthesia.