title: Pitfalls in diagnosing PFO: characteristics of false-negative contrast injections during transesophageal echocardiography in patients with patent foramen ovales.
abstract: BACKGROUND
  Contrast injections during transesophageal echocardiography for patent foramen ovale (PFO) detection may be false negative. The characteristics of false-negative injections were studied retrospectively.
  
  
  METHODS
  Contrast transesophageal echocardiography was analyzed for the presence or absence of two characteristics: leftward bulging of the interatrial septum and dense contrast filling of the region of the right atrium adjacent to the interatrial septum.
  
  
  RESULTS
  Two hundred forty-seven injections were administered to 14 patients with PFOs, and 130 (53%) were false negative. The absence of either characteristic during a single injection resulted in low sensitivity for PFO detection of 7%. When the two characteristics were present at the same time, the sensitivity for PFO detection after a single injection was as high as 95%.
  
  
  CONCLUSIONS
  The simultaneous presence of both leftward bulging of the interatrial septum and dense contrast filling of the region in the right atrium, adjacent to the interatrial septum, is a prerequisite for PFO detection, and if either characteristic is missing, the injection is inconclusive.
authors.affiliation: Department of Emergency and Cardiovascular Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. magnus.c.johansson@vgregion.se
authors.forename: Magnus C
authors.initials: MC
authors.lastname: Johansson
authors.forename: Peter
authors.initials: P
authors.lastname: Eriksson
authors.forename: Cecilia Wallentin
authors.initials: CW
authors.lastname: Guron
authors.forename: Mikael
authors.initials: M
authors.lastname: Dellborg
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015331:Cohort Studies; D003287:Contrast Media; D017548:Echocardiography, Transesophageal / Q000009:adverse effects / Q000379:methods*; D005188:False Negative Reactions; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011097:Polygeline; D012016:Reference Values; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media; D011097:Polygeline