title: Importance of adequately performed Valsalva maneuver to detect patent foramen ovale during transesophageal echocardiography.
abstract: BACKGROUND
  Transesophageal echocardiography (TEE) plays an important role in evaluating cardioembolic sources of emboli. The identification of a patent foramen ovale (PFO) is reportedly improved with TEE compared with transthoracic echocardiography (TTE), but the Valsalva maneuver during TEE may be difficult or suboptimal. The aim of this study was to assess the efficacy of the Valsalva maneuver for PFO diagnosis using TEE compared with TTE by evaluating patients with ischemic stroke referred for echocardiography.
  
  
  METHODS
  Only patients able to perform the Valsalva maneuver during TTE were included; efficacy was defined by a 20 cm/sec decrease in transmitral E velocity. A PFO was judged present when microbubbles of agitated intravenous saline were seen in the left chambers within three cycles after right atrial opacification.
  
  
  RESULTS
  Of 108 patients (mean age, 55 ± 15 years; 61 men), 48 (44%) were judged to have PFOs by TEE and/or TTE. In 36 patients (33% of the total, 75% of those with PFOs), microbubbles were observed both by TEE and TTE, in seven patients only during TTE, and in five patients only during TEE. In patients able to satisfactorily perform the Valsalva maneuver during TEE, 22 PFOs were found, and two shunts (9%) were missed, whereas in patients unable to perform this maneuver, 26 PFOs were observed, with five shunts missed (19%) (P < .05). When a PFO was missed by TTE, either the echocardiographic window was suboptimal or the shunt was small.
  
  
  CONCLUSIONS
  An adequate Valsalva maneuver is crucial for diagnosis of PFO; most patients with stroke may be screened using TTE with contrast and the Valsalva maneuver, with TEE indicated in case of suboptimal transthoracic images.
authors.affiliation: Echocardiography Laboratory, Radiology Institute InRad, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil. Electronic address: claratude@yahoo.com.
authors.forename: Ana Clara
authors.initials: AC
authors.lastname: Rodrigues
authors.forename: Michael H
authors.initials: MH
authors.lastname: Picard
authors.forename: Aime
authors.initials: A
authors.lastname: Carbone
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Arruda
authors.forename: Thaís
authors.initials: T
authors.lastname: Flores
authors.forename: Juliana
authors.initials: J
authors.lastname: Klohn
authors.forename: Meive
authors.initials: M
authors.lastname: Furtado
authors.forename: Edgar B
authors.initials: EB
authors.lastname: Lira-Filho
authors.forename: Giovanni G
authors.initials: GG
authors.lastname: Cerri
authors.forename: José L
authors.initials: JL
authors.lastname: Andrade
mesh_terms: D001938:Brazil / Q000453:epidemiology; D015984:Causality; D015897:Comorbidity; D017548:Echocardiography, Transesophageal / Q000706:statistics & numerical data*; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology*; D014636:Valsalva Maneuver
keywords: CVA; Cerebrovascular accident; PFO; Patent foramen ovale; TEE; TTE; Transesophageal echocardiography; Transthoracic echocardiography; Valsalva maneuver