title: Cerebral microemboli during left heart catheterization.
abstract: BACKGROUND
  The aim of this study was to describe the rate of microemboli signals (MES) during left heart catheterization (LHC).
  
  
  METHODS
  A monitoring of both middle cerebral arteries using transcranial Doppler ultrasonography was performed to investigate cerebral microemboli during LHC. Seventy-two patients undergoing LHC and 29 patients with LHC followed by coronary intervention were studied.
  
  
  RESULTS
  During a standardized LHC (n = 52), 95 +/- 45 MES were detected of which 67.5% occurred during injection of contrast media or saline solution, 30% during movements of wire and catheter, and 2% during catheter manipulation. During coronary interventions only, rotablation (n = 2) was followed by a massive increase in MES. The use of injection fluids prepared with minor gas content reduced the MES rate by 67% (P <.05). All MES were clinically silent.
  
  
  CONCLUSIONS
  Cerebral microembolism is a current finding during LHC. The dependence of the MES rate during diagnostic LHC on the gas content of the injection fluids provides evidence that most of the MES are caused by microbubbles and not by solid emboli. The high rate of MES during coronary rotablation may be explained by the formation of cavitation bubbles. The clinical results of the MES during LHC appear to be benign.
authors.affiliation: Department of Neurology, University of the Saarland, Homburg/Saar, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Fischer
authors.forename: C
authors.initials: C
authors.lastname: Ozbek
authors.forename: W
authors.initials: W
authors.lastname: Bay
authors.forename: G F
authors.initials: GF
authors.lastname: Hamann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization / Q000009:adverse effects*; D003287:Contrast Media; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D003287:Contrast Media