Researchers warn of potentially fatal condition for open water swimmers | Swimming
A potentially life-threatening condition that can affect fit and healthy open-water swimmers by causing them to “drown from the inside” may involve a build-up of fluid in the heart muscle, researchers suggest.
Swimming-induced pulmonary edema – SIPE – is a form of immersion pulmonary edema and involves the accumulation of fluid in the swimmer’s lungs without being inhaled. The condition is thought to be the result of increased pressure on the body’s blood vessels as a result of exertion, immersion and cold.
The condition can cause difficulty breathing, low oxygen levels in the blood, coughing, frothy or bloody sputum and, in some cases, death.
“I guess most people die in the water [having entered voluntarily] – that is, swimmers or divers – die from immersion pulmonary oedema, not drowning,” said Dr Peter Wilmshurst, consultant cardiologist at Royal Stoke University Hospital and member of the UK Medical Board for Diving, who first described IPE in the 1980s .
Wilmshurst added that the condition is far from rare: about 1 of 200 people taking part in Sweden’s annual race, the Vansbro Swimget SIPE, doc 1 in 20 young men are reported to have the condition during selection for the US Navy SEALs.
While cases often occur in people who are fit and healthy, there are a number of known risk factors, including age, high blood pressure, being female and swimming in cold water.
Figures from Sport England show that around 2.7 million people took part in open water swimming in England between November 2020 and November 2021.
The UK medical team that diagnosed IPE in a fit and healthy woman in her 50s, who had been swimming in 17C open water, say they discovered a build-up of fluid in her heart muscle.
“While it is conceivable that this represents a pre-existing inflammatory process such as myocarditis, which contributed to the IPE, it is also a potential consequence of the acute episode,” the team he wrote in the journal BMJ case reportsnoting that it is not the first report of cardiac muscle dysfunction in the context of IPE.
The woman described how she had difficulties while participating in a nighttime swim at the quarry. “When I got out, I unzipped my wetsuit and immediately felt my lungs fill with fluid,” she said, noting that she developed a cough and foamy pink sputum. “I was very fortunate to be surrounded by a great team at the quarry who knew I had SIPE.”
The woman’s symptoms resolved within two hours of arriving at the emergency department and she was discharged from the hospital the next day.
The authors say that although the woman received a booster shot of Covid several hours before swimming, it is unlikely that this was related to IPE. Indeed, the woman noted that she experienced a milder form of shortness of breath after swimming in the sea two weeks ago and during another exercise. “I just assumed I was a bit unwell,” she said in the report.
Wilmshurt, who was not involved in compiling the report, also said it was unlikely that the vaccination caused the fluid in the heart muscle, given the short time between the injection and the onset of symptoms. While it was not possible to say whether it was caused by the IPE or a pre-existing condition, he said, he suspects the former.
dr. Doug Watts, medical director of diving medicine specialist DDRC Healthcare, said people should be aware of IPE, and get out of the water and seek medical attention immediately if they notice they are unusually short of breath while swimming. “If you have one episode, you’re likely to have another episode, and the next one could be fatal,” he said.
Wilmshurst said it was important not to go swimming alone in open water and noted the need for medical attention in the case of IPE. “If you get it … it could be the first sign that you have underlying heart disease or hypertension,” he said.