title: Effect of catheter-based patent foramen ovale closure on the occurrence of arterial bubbles in scuba divers.
abstract: OBJECTIVE
  This study sought to evaluate the effect of catheter-based patent foramen ovale (PFO) closure on the occurrence of arterial bubbles after simulated dives.
  
  
  BACKGROUND
  PFO is a risk factor of decompression sickness in divers due to paradoxical embolization of bubbles. To date, the effectiveness of catheter-based PFO closure in the reduction of arterial bubbles has not been demonstrated.
  
  
  METHODS
  A total of 47 divers (age 35.4 ± 8.6 years, 81% men) with a PFO (PFO group) or treated with a catheter-based PFO closure (closure group) were enrolled in this case-controlled observational trial. All divers were examined after a simulated dive in a hyperbaric chamber: 34 divers (19 in the PFO group, 15 in the closure group) performed a dive to 18 m for 80 min, and 13 divers (8 in the PFO group, 5 in the closure group) performed a dive to 50 m for 20 min. Within 60 min after surfacing, the presence of venous and arterial bubbles was assessed by transthoracic echocardiography and transcranial color-coded sonography, respectively.
  
  
  RESULTS
  After the 18-m dive, venous bubbles were detected in 74% of divers in the PFO group versus 80% in the closure group (p = 1.0), and arterial bubbles were detected in 32% versus 0%, respectively (p = 0.02). After the 50-m dive, venous bubbles were detected in 88% versus 100%, respectively (p = 1.0), and arterial bubbles were detected in 88% versus 0%, respectively (p < 0.01).
  
  
  CONCLUSIONS
  No difference was observed in the occurrence of venous bubbles between the PFO and closure groups, but the catheter-based PFO closure led to complete elimination of arterial bubbles after simulated dives. (Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure; NCT01854281).
authors.affiliation: Department of Cardiology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic; Institute of Pathological Physiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Honěk
authors.affiliation: Institute of Pathological Physiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic; Department of Neurology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Srámek
authors.affiliation: Institute of Pathological Physiology, Charles University in Prague, First Faculty of Medicine, Prague, Czech Republic.
authors.forename: Luděk
authors.initials: L
authors.lastname: Sefc
authors.affiliation: Cardiocentrum, Hospital Podlesí, Třinec, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Januška
authors.affiliation: Department of Cardiology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Fiedler
authors.affiliation: Department of Cardiology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Horváth
authors.affiliation: Department of Neurology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
authors.forename: Aleš
authors.initials: A
authors.lastname: Tomek
authors.affiliation: Hyperbaric Chamber, Kladno Regional Hospital, Kladno, Czech Republic.
authors.forename: Stěpán
authors.initials: S
authors.lastname: Novotný
authors.affiliation: Department of Cardiology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Honěk
authors.affiliation: Department of Cardiology, Charles University in Prague, Second Faculty of Medicine and Motol University Hospital, Prague, Czech Republic. Electronic address: veselka.josef@seznam.cz.
authors.forename: Josef
authors.initials: J
authors.lastname: Veselka
mesh_terms: D000328:Adult; D006328:Cardiac Catheterization / Q000295:instrumentation; D016022:Case-Control Studies; D003665:Decompression Sickness / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D004242:Diving / Q000009:adverse effects*; D017548:Echocardiography, Transesophageal; D004618:Embolism, Air / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D055989:Septal Occluder Device; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
keywords: catheter-based closure; decompression sickness; paradoxical embolization; patent foramen ovale