title: Clinical and electroencephalographic features of carotid sinus syncope induced by internal carotid artery angioplasty.
abstract: OBJECTIVE
  Carotid sinus syncope may occur acutely during internal carotid artery angioplasty (CA). We performed this study to investigate the clinical, electroencephalographic (EEG), and hemodynamic features of carotid sinus syncope induced by CA.
  
  
  METHODS
  Between 1992 and 2003, clinical, EEG, and cardiovascular monitoring was performed in 359 consecutive patients undergoing CA.
  
  
  RESULTS
  Carotid sinus reaction (CSR) and syncope occurred in 62.7% and 18.6% of the procedures, respectively. CSR and syncopal spells were classified into cardioinhibitory, vasodepressor, and mixed type. Syncope occurred more frequently in patients with cardioinhibitory CSR (P < .001). The odds ratios for the risk of syncope in patients with cardioinhibitory CSR and vasodepressor/mixed CSR were 6.9 and 1.4, respectively. Sixty-one patients had cardioinhibitory syncope; 7 had the vasodepressor/mixed type. Thirteen spells were not related to cardiovascular disturbances. This last syncope subtype was significantly associated with brain hemodynamic disturbances, including a decrease in cerebral vasoreactivity (P = .04) and the absence of function of both communicating arteries (P = .03). Convulsive movements resembling supplementary sensorimotor seizures occurred in 79% of patients who experienced syncopal spells. EEG changes were more prominent in patients with cardioinhibitory syncope.
  
  
  CONCLUSIONS
  Syncope occurs frequently in patients undergoing CA and can be misdiagnosed as seizures. The most frequent mechanism was a cardioinhibitory response. Cerebral hemodynamic disturbances may play a crucial role in the pathophysiology of syncope with normal sinus rhythm and normotension. Moreover, direct depression of the CNS following carotid sinus distension is likely to be involved.
authors.affiliation: Department of Neurology, Hospitales Universitarios Virgen del Rocio, Seville, Spain. emartinezf@ya.com
authors.forename: E
authors.initials: E
authors.lastname: Martinez-Fernandez
authors.forename: F Boza
authors.initials: FB
authors.lastname: García
authors.forename: J R
authors.initials: JR
authors.lastname: Gonzalez-Marcos
authors.forename: A Gil
authors.initials: AG
authors.lastname: Peralta
authors.forename: A Gonzalez
authors.initials: AG
authors.lastname: Garcia
authors.forename: A Mayol
authors.initials: AM
authors.lastname: Deya
mesh_terms: D000800:Angioplasty, Balloon / Q000706:statistics & numerical data*; D016893:Carotid Stenosis / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D015897:Comorbidity; D004569:Electroencephalography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013575:Syncope / Q000175:diagnosis* / Q000453:epidemiology*; D016896:Treatment Outcome