title: Risk of decompression illness among 230 divers in relation to the presence and size of patent foramen ovale.
abstract: BACKGROUND
  The risk of developing decompression illness (DCI) in divers with a patent foramen ovale (PFO) has not been directly determined so far; neither has it been assessed in relation to the PFO's size.
  
  
  METHODS
  In 230 scuba divers (age 39+/-8 years), contrast trans-oesophageal echocardiography (TEE) was performed for the detection and size grading (0-3) of PFO. Prior to TEE, the study individuals answered a detailed questionnaire about their health status and about their diving habits and accidents. For inclusion into the study, > or =200 dives and strict adherence to decompression tables were required.
  
  
  RESULTS
  Sixty-three divers (27%) had a PFO. Overall, the absolute risk of suffering a DCI event was 2.5 per 10(4) dives. There were 18 divers (29%) with, and 10 divers (6%) without, PFO who had experienced > or =1 major DCI events P=0.016. In the group with PFO, the incidence per 10(4) dives of a major DCI, a DCI lasting longer than 24 h and of being treated in a decompression chamber amounted to 5.1 (median 0, interquartile range [IQR] 0-10.0), 1.9 (median 0, IQR 0-4.0) and 3.6 (median 0, IQR 0-9.8), respectively and was 4.8-12.9-fold higher than in the group without PFO (P<0.001). The risk of suffering a major DCI, of a DCI lasting longer than 24 h and of being treated by recompression increased with rising PFO size.
  
  
  CONCLUSIONS
  The presence of a PFO is related to a low absolute risk of suffering five major DCI events per 10(4) dives, the odds of which is five times as high as in divers without PFO. The risk of suffering a major DCI parallels PFO size.
authors.affiliation: Department of Cardiology, University Hospital, CH-3010 Bern, Switzerland.
authors.forename: Sandra Rea
authors.initials: SR
authors.lastname: Torti
authors.forename: Michael
authors.initials: M
authors.lastname: Billinger
authors.forename: Markus
authors.initials: M
authors.lastname: Schwerzmann
authors.forename: Rolf
authors.initials: R
authors.lastname: Vogel
authors.forename: Rainer
authors.initials: R
authors.lastname: Zbinden
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
authors.forename: Christian
authors.initials: C
authors.lastname: Seiler
mesh_terms: D003665:Decompression Sickness / Q000209:etiology* / Q000473:pathology; D004242:Diving / Q000009:adverse effects* / Q000706:statistics & numerical data; D017548:Echocardiography, Transesophageal / Q000379:methods; D005260:Female; D006304:Health Status; D006344:Heart Septal Defects, Atrial / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors