Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers.

BACKGROUND

In divers, the significance of a patent foramen ovale and its potential relation to paradoxical gas emboli remain uncertain.

OBJECTIVE

To assess the prevalence of symptoms of decompression illness and ischemic brain lesions in divers with regard to the presence of a patent foramen ovale.

DESIGN

Retrospective cohort study.

SETTING

University hospital and three diving clubs in Switzerland.

PARTICIPANTS

52 sport divers and 52 nondiving controls.

MEASUREMENTS

Prevalence of self-reported decompression events, patent foramen ovale on contrast transesophageal echocardiography, and ischemic brain lesions on magnetic resonance imaging.

RESULTS

The risk for decompression illness events was 4.5-fold greater in divers with patent foramen ovale than in divers without patent foramen ovale (risk ratio, 4.5 [95% CI, 1.2 to 18.0]; P = 0.03). Among divers, 1.23 +/- 2.0 and 0.64 +/- 1.22 ischemic brain lesions per person (mean +/- SD) were detected in those with and those without patent foramen ovale, respectively. Among controls, 0.22 +/- 0.44 and 0.12 +/- 0.63 lesion per person were detected (P < 0.001 for all groups).

CONCLUSIONS

Regardless of whether a diver has a patent foramen ovale, diving is associated with ischemic brain lesions.