Persistent (patent) foramen ovale (PFO): implications for safe diving.

Area of Science:

• Diving medicine integrates physics, physiology, and molecular science to understand immersion/emersion effects.
• Research in diving medicine benefits from non-diving medical fields like cardiology and neurology.
• Investigating the role of Patent Foramen Ovale (PFO) in diving-related incidents is crucial.

Background:

• Patent Foramen Ovale (PFO) is a cardiac condition studied for stroke and migraine associations.
• PFO closure devices offer a seemingly low-risk solution, but results in non-diving populations are debated.
• In diving, PFO is a potential pathway for venous gas emboli (VGE) to arterialize, causing decompression illness (DCI).

Discussion:

• The risk-benefit ratio of PFO closure for divers is unclear, with procedure risks potentially exceeding DCI risks.
• Accurate PFO prevalence in divers is unknown due to diagnostic challenges and protocol variations.
• Conservative dive profiles significantly reduce DCI risk, even in divers with PFO, suggesting behavioral modification is key.

Key Insights:

• PFO closure can reduce VGE arterialization but carries inherent health risks.
• The effectiveness of PFO closure in preventing DCI is not absolute and depends heavily on dive profiles.
• Promoting PFO closure for divers without comprehensive risk-benefit analysis is ethically questionable.

Outlook:

• Further prospective studies are needed to evaluate PFO closure's true impact on DCI incidence, costs, and side effects in divers.
• Divers must be informed about the risks and benefits to make educated decisions, rather than relying on simplistic 'fix it' notions.
• Understanding PFO-related DCI offers insights into gas bubble effects on tissues and reinforces the importance of learned safe diving practices.