SCUBA divers with PFO at higher risk for decompression illness than previously thought

 

Abstract: https://www.acpjournals.org/doi/10.7326/M23-0260  

URL goes live when the embargo lifts

A study of a cohort of SCUBA divers has found that the presence of high-risk patent foramen ovale (PFO), or a hole in the heart, was associated with an increased risk of decompression illness (DCI), also commonly known as the bends. The authors recommend that divers with high-risk PFO should consider either refraining from diving or adhering to a conservative diving protocol. The findings are published in Annals of Internal Medicine.

DCI is a disease in which inhaled nitrogen is dissolved in tissues or blood under a high pressure during a diver’s descent and subsequently forms gas bubbles while they rise, mechanically affecting the tissue or inhibiting blood flow. A PFO enables venous nitrogen bubbles to embolize into the arterial system. In previous studies, a higher prevalence of PFO was seen in divers who experienced DCI than in those whodid not. However, the association between PFO and DCI remains uncertain given the very low prevalence of DCI compared with the high prevalence of PFO.

Researchers from Sejong Hospital, Bucheon, South Korea conducted a prospective cohort study of 100 experienced divers who did more than 50 dives per year. Participants had transesophageal echocardiography with a saline bubble test to determine the presence of a PFO and were subsequently divided into high- and low risk groups. They were followed up using a self-reported questionnaire while blinded to their PFO status. The authors report that 12 of 68 divers with PFO (10 of 37 divers with high-risk PFO) experienced DCI. These findings suggest that divers with high-risk PFO are more susceptible to DCI than has been previously reported. According to the authors, their findings also suggest that DCI events with mild symptoms occurred frequently in divers with PFO, and many divers did not recognize them as DCI.

 

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