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.