Influence of repetitive open sea dives and physical exercises on right-to-left shunting in healthy divers.
OBJECTIVE
Paradoxical gas embolism through right-to-left (R/L) shunts is considered as a potential cause of certain types of decompression sickness.


OBJECTIVE
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.


CONCLUSIONS
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.
Département de Médecine Hyperbare, Hôpital d'instruction des armées Sainte-Anne, 83800 Toulon Armées, France. je.blatteau@infonie.fr
J-E
JE
Blatteau
C
C
Pény
J-M
JM
Pontier
E
E
Gempp
P
P
Louge
D000328:Adult; D003664:Decompression / Q000009:adverse effects; D003665:Decompression Sickness / Q000000981:diagnostic imaging / Q000209:etiology*; D004242:Diving / Q000502:physiology*; D004618:Embolism, Air / Q000150:complications* / Q000000981:diagnostic imaging; D019320:Embolism, Paradoxical / Q000150:complications* / Q000000981:diagnostic imaging; D015444:Exercise / Q000502:physiology*; D054092:Foramen Ovale, Patent / Q000150:complications; D006801:Humans; D008889:Military Personnel; D011652:Pulmonary Circulation / Q000502:physiology*; D017585:Ultrasonography, Doppler, Transcranial