Recurrent episodes of asystole from carotid sinus hypersensitivity triggered by positioning for head and neck surgery.

BACKGROUND We present a case report of a patient with recurrent thyroid carcinoma, previously treated with surgery and radiotherapy, who developed asystolic episodes on 2 occasions as the result of positioning of the neck in hyperextension for head and neck surgery. METHODS AND RESULTS In carotid sinus hypersensitivity (CSH), the carotid sinus reflex is greatly exaggerated, resulting in profound bradycardia and asystole. Predisposing risk factors for the development of CSH in this patient included history of previously treated head and neck cancer and the presence of tight surgical scars. His negative cardiovascular history, the time sequence between neck positioning and asystole, and the fact that asystole recurred during the second surgery strongly suggest that CSH was precipitated by hyperextension of the neck during positioning. CONCLUSIONS A heightened awareness of this syndrome, close monitoring, and preparedness for timely diagnosis and management are essential for a successful outcome.