title: Doppler microembolic signals in patients with two different types of bileaflet valves.
abstract: OBJECTIVE
  This study was performed to evaluate the prevalence and counts of Doppler microembolic signals in patients with St Jude Medical valves (St Jude Medical, Inc, St Paul, Minn) and patients with ATS valves (ATS Medical, Inc, Minneapolis, Minn) and their relation to clinical parameters.
  
  
  METHODS
  A total of 179 outpatients of the department of cardiothoracic surgery were examined. They included 98 men and 81 women, aged 61 +/- 11 years, with ATS (n = 91) or St Jude Medical (n = 88) valves in the aortic (n = 110), mitral (n = 39), or both positions (n = 30). Neurologic examination was followed by transcranial Doppler monitoring for microembolic signals. Monitoring was performed bilaterally over the middle cerebral arteries for 1 hour per session.
  
  
  RESULTS
  Microembolic signal counts and prevalence were significantly higher in patients with St Jude Medical as compared with ATS valves. Valve type and presence of diabetes mellitus were the only predictors of microembolic signal prevalence on multivariate analysis. No influence of microembolic signals on cerebral embolic complications was established. Additionally, patients with a postoperative history of cerebral embolic complications did not have a higher number of microembolic signals than remaining patients. Interobserver variability was satisfactory.
  
  
  CONCLUSIONS
  Patients with St Jude Medical valves were shown to have significantly higher microembolic signal counts than patients with ATS valves. However, our results suggest that microembolic signal counts cannot be used to predict cerebral embolic complications. Their relation to neuropsychologic deficits remains to be evaluated.
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany. dimitrios.georgiadis@medizin.uni-halle.de
authors.forename: D
authors.initials: D
authors.lastname: Georgiadis
authors.forename: S
authors.initials: S
authors.lastname: Braun
authors.forename: F
authors.initials: F
authors.lastname: Uhlmann
authors.forename: G M
authors.initials: GM
authors.lastname: Bernacca
authors.forename: W J
authors.initials: WJ
authors.lastname: Schulte-Mattler
authors.forename: S
authors.initials: S
authors.lastname: Zierz
authors.forename: H R
authors.initials: HR
authors.lastname: Zerkowski
mesh_terms: D000368:Aged; D001022:Aortic Valve Insufficiency / Q000601:surgery*; D004869:Equipment Safety; D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000601:surgery*; D015588:Observer Variation; D015995:Prevalence; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012307:Risk Factors; D018709:Statistics, Nonparametric; D018608:Ultrasonography, Doppler