Recurrent Episodes of Asystolia Induced by Carotid Sinus Manipulation During Cervical Spine Surgery Without Preceding Clinical Symptoms

We report a unique case of recurrent asystolic episodes arising from carotid sinus hypersensitivity (CSH), during surgical intervention for cervical disk prolapse under general anesthesia. As the patient’s neck was positioned for optimal surgical exposure, an incidence of cardiac arrest lasting 5.8 seconds was detected that was restored to normal sinus rhythm by cessation of any manipulation in the neck and intravenous administration of atropine 0.5 mg. The incidence recurred twice and it was again elicited from light manipulations at the right side of the neck, where the surgical procedure was going to be performed. An extremely sensitive carotid sinus reflex was suspected, but as the surgical procedure could not be postponed owing to its urgent nature, a temporary pacing establishment was decided. Thereafter, having the temporary pacemaker in situ at demand function, surgical intervention was completed uneventfully. Recurrent episodes of bradycardia were recorded at several time-points throughout the surgical procedure, which was effectively managed by the ventricular pacing. The postoperative course was uneventful. Our case comes to highlight the importance of heightened awareness of CSH as this syndrome constitutes an unexpected but potentially lethal entity during positioning for cervical spine surgery. Considering that, the intraoperative period itself poses significant challenges, high clinical suspicion, early identification of the signs of possible CSH, close hemodynamic monitoring, and immediate availability of vagolytic drugs, b-1 stimulators, and intraoperative cardiac pacing are the key elements for an early diagnosis, timely management, and a favorable outcome.