title: Recurrent episodes of asystole from carotid sinus hypersensitivity triggered by positioning for head and neck surgery.
abstract: 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.
  
  
  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.
authors: Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA. atruong@mdanderson.org
authors: Angela T
authors: AT
authors: Truong
authors: Erich M
authors: EM
authors: Sturgis
authors: Marc A
authors: MA
authors: Rozner
authors: Dam-Thuy
authors: DT
authors: Truong
mesh_terms: D000328:Adult; D002346:Carotid Sinus / Q000503:physiopathology*; D006323:Heart Arrest / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D056888:Patient Positioning / Q000009:adverse effects*; D011183:Postoperative Complications / Q000175:diagnosis*; D012008:Recurrence; D012021:Reflex, Abnormal; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000601:surgery*