Swiss medical weekly
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Swiss medical weekly · Jun 2001
ReviewRecreational scuba diving, patent foramen ovale and their associated risks.
Scuba diving has become a popular leisure time activity with distinct risks to health owing to its physical characteristics. Knowledge of the behaviour of any mixture of breathable gases under increased ambient pressure is crucial for safe diving and gives clues as to the pathophysiology of compression or decompression related disorders. Immersion in cold water augments cardiac pre- and afterload due to an increase of intrathoracic blood volume and peripheral vasoconstriction. ⋯ There is ongoing debate about the long term risk of scuba diving. Neuro-imaging studies revealed an increased frequency of ischaemic brain lesions in divers, which do not correlate well with subtle functional neurological deficits in experienced divers. In the light of the high prevalence of venous gas bubbles even after dives in shallow water and the presence of a cardiac right-to-left shunt in a quarter of the population (i.e., patent foramen ovale), arterialisation of gas bubbles might be more frequent than usually presumed.