title: Cerebral microembolism detected by transcranial Doppler during cardiac procedures.
abstract: OBJECTIVE
  Cerebral embolism with clinical sequelae may rarely complicate cardioversion and cardiac catheterization. Transcranial Doppler sonography has recently been introduced to monitor microemboli entering the middle cerebral artery in cardiac and carotid surgery. We therefore used this technique to evaluate the risk of asymptomatic embolism during common cardiac procedures.
  
  
  METHODS
  Patients were monitored by transcranial Doppler while undergoing direct current cardioversion (n=15) and cardiac catheterization (n=17).
  
  
  RESULTS
  Microemboli were detected in all patients having cardiac catheterization but in only 1 patient after cardioversion.
  
  
  CONCLUSIONS
  Microembolism occurred frequently during cardiac catheterization and rarely during cardioversion. It is not yet known whether this has clinical relevance.
authors.affiliation: Departments of Neurological Studies, Department of Cardiovascular Medicine, University College London Hospitals and Medical School, London, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Stygall
authors.forename: R
authors.initials: R
authors.lastname: Kong
authors.forename: J M
authors.initials: JM
authors.lastname: Walker
authors.forename: S M
authors.initials: SM
authors.lastname: Hardman
authors.forename: M J
authors.initials: MJ
authors.lastname: Harrison
authors.forename: S P
authors.initials: SP
authors.lastname: Newman
mesh_terms: D006328:Cardiac Catheterization / Q000009:adverse effects*; D004554:Electric Countershock / Q000009:adverse effects*; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D016343:Monitoring, Intraoperative; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial