Influence of repetitive open sea dives and physical exercises on right-to-left shunting in healthy divers
- 1Département de Médecine Hyperbare, Hôpital d’instruction des armées Sainte-Anne, Toulon Armées, France
- 2Ecole de Plongée de la Marine, Toulon Armées, France
- 3Institut de Médecine Navale du Service de Santé des Armées IMNSSA, Toulon Armées, France
- J-E Blatteau, Département Hyperbare, HIA Sainte-Anne, 83800 Toulon Armées, France; je.blatteau{at}infonie.fr
- Accepted 20 November 2007
- Published Online First 7 December 2007
Abstract
Objective: Paradoxical gas embolism through right-to-left (R/L) shunts is considered as a potential cause of certain types of decompression sickness.
Aim: To assess whether 4 months of repetitive diving and strenuous exercises would lead to an increased prevalence of R/L shunting in a group of military divers.
Methods: Using a standardised contrast-enhanced transcranial Doppler technique, 17 divers were re-examined for the presence of a R/L shunt 4 months after their initial examinations. R/L shunts were classified as type I if observed only after a straining manoeuvre, and type II if present at rest.
Results: Initial prevalence of R/L shunt was 41%: six type I shunts and one type II. At the second examination, prevalence was 47%, with the appearance of one type I shunt that was not previously present. We found no significant increase in the prevalence and size of R/L shunts.
Conclusion: It is speculated that diving-related phenomena, such as variations in right atrial pressures during the end stages of or events immediately after a dive could generate an R/L shunt. However, extreme conditions of repetitive diving and strenuous exercises do not cause permanent modification in R/L permeability over a period of 4 months.
Footnotes
-
Funding: There is no financial or other relationship that might be perceived as leading to a conflict of interest.
-
Competing interests: None.







