Prolonged cardiac arrest unveiled silent sick sinus syndrome during general and epidural anesthesia

Patients who have silent sick sinus syndrome (SSS) can show various unexpected arrhythmias during surgery. The severity of these bradyarrythmias is affected by anesthetic methods. We report a unique case of a patient with silent SSS who developed 40 s of asystole under combined general and epidural anesthesia. A 40-year-old woman with no apparent cardiac disease underwent abdominal hysterectomy. General anesthesia was induced and maintained with propofol, fentanyl, and vecuronium combined with thoracic epidural anesthesia. During surgery, severe bradycardia, triggered by peritoneal manipulation, occurred, leading to 40 s of asystole. She was diagnosed as having SSS by a postoperative 24-h Holter electrocardiogram. We propose that the possible existence of SSS should be kept in mind even in a patient who shows no abnormalities on routine preoperative examination, especially in those in whom vagomimetic anesthetic methods are used.