Decompression Illness in Divers With or Without Patent Foramen Ovale : A Cohort Study

In previous studies, the prevalence of patent foramen ovale (PFO) has been reported to be higher in scuba divers who experienced decompression illness (DCI) than in those who did not.

To assess the association between PFO and DCI in scuba divers.

Prospective cohort study.

Tertiary cardiac center in South Korea.

One hundred experienced divers from 13 diving organizations 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 using a self-reported questionnaire while blinded to their PFO status. All of the reported symptoms were adjudicated in a blinded manner. The primary end point of this study was PFO-related DCI. Logistic regression analysis was done to determine the odds ratio of PFO-related DCI.

Patent foramen ovale was seen in 68 divers (37 at high risk and 31 at low risk). Patent foramen ovale-related DCI occurred in 12 divers in the PFO group (non-PFO vs. high-risk PFO vs. low-risk PFO: 0 vs. 8.4 vs. 2.0 incidences per 10 000 person-dives; P = 0.001) during a mean follow-up of 28.7 months. Multivariable analysis showed that high-risk PFO was independently associated with an increased risk for PFO-related DCI (odds ratio, 9.34 [95% CI, 1.95 to 44.88]).

The sample size was insufficient to assess the association between low-risk PFO and DCI.

High-risk PFO was associated with an increased risk for DCI in scuba divers. This finding indicates that divers with high-risk PFO are more susceptible to DCI than what has been previously reported and should consider either refraining from diving or adhering to a conservative diving protocol.

Sejong Medical Research Institute.