title: Enhanced detection of patent foramen ovale by systematic transthoracic saline contrast echocardiography.
abstract: OBJECTIVE
  We aimed to evaluate the effectiveness of transthoracic saline contrast echocardiography (TSCE) in detecting patent foramen ovale (PFO).
  
  
  BACKGROUND
  Transesophageal echocardiography (TEE) is semi-invasive and not ideal for PFO screening.
  
  
  METHODS
  112 patients (48 males, 46 ± 14 years) with suspected PFO received intravenous agitated-saline contrast at rest and stress (strain and release phases of Valsalva maneuver and coughing). The presence of interatrial shunting was defined as >5 bubbles appearing in the left heart within 3 cardiac cycles. The stage of the maneuver at which interatrial shunting occurred was recorded. The TSCE findings were validated by TEE.
  
  
  RESULTS
  TEE identified PFO in 45% of patients. The sensitivities of TSCE in detecting PFO at rest, during strain and release of Valsalva maneuver, and coughing were 12.0%, 38.0%, 80.0% and 94.0% respectively (each p<0.05 when compared to previous stage). Specificities were similar and >95% for all stages. Moreover, the release phase of the maneuver improved the diagnostic accuracy [defined as (number of true positives+true negatives) divided by total in sample] with incremental value over the preceding strain phase (89.2 vs. 70.5%, p<0.001).
  
  
  CONCLUSIONS
  Patent foramen ovale can be identified confidently with proper conduct of the Valsalva maneuver during the transthoracic saline contrast echocardiography.
authors.affiliation: Division of Cardiology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, Peoples’ Republic of China.
authors.forename: Yat-Yin
authors.initials: YY
authors.lastname: Lam
authors.forename: Cheuk-Man
authors.initials: CM
authors.lastname: Yu
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Bryan P
authors.initials: BP
authors.lastname: Yan
authors.forename: Gabriel Wai-Kwok
authors.initials: GW
authors.lastname: Yip
mesh_terms: D000328:Adult; D003287:Contrast Media; D003371:Cough; D004452:Echocardiography / Q000379:methods*; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012146:Rest; D012680:Sensitivity and Specificity; D012965:Sodium Chloride; D014636:Valsalva Maneuver
chemical_list: D003287:Contrast Media; D012965:Sodium Chloride