Diving into the Heart of Trouble

Divers can be cocky and cranky, refusing to admit they're getting older and should consider their medical issues before plunging into the water. That can lead to fatal errors. In the U.K., recent dive incident data shows increasing dive fatalities in the 50-and-over age group, a fair number of them due to heart attacks in the water. On a related note, two recent studies show that 10 percent of divers surveyed took medications for primary or secondary prevention of heart disease.

We've written frequently about how some countries, like Australia, are strict in requiring divers to show proof of good health and fitness before going out with a dive operator, while other countries, like the U.S., are more laissez-faire about it. Marguerite St Leger Dowse, a veteran researcher at England's Diving Diseases Research Centre, says the U.K. falls in the latter camp, and that "the compulsion to undergo diving medical/ self-certification is limited."

She created an online survey for divers to collect data on diving demographics, their prescribed medications, diagnosed hypertension, other health issues and habits when it comes to smoking, alcohol and exercise. A total of 672 divers responded, three-quarters of them male with a mean age of 44. Twenty-seven percent of them had never had a dive medical, and another 11 percent had not had one in the last 10 years. High blood pressure was reported by 18 percent of the divers; 21 percent of that group had never had a diving medical exam.

Patent foramen ovale (PFO), a relatively benign cardiac defect that creates a passage in a wall between the left and right upper chambers of the heart, increases the risk of bends in divers. Of the respondents, 28 report having a PFO, with 20 of them opting for a procedure to close it. Of 83 divers treated for decompression sickness in the past, 19 of them had a PFO.

The responses show that divers who inevitably develop heart problems will continue to dive, but not all of them will have a medical examination to determine whether they're still fit to dive. Dowse speculates that because treatment of dive-related illness is free for U.K. residents, the lack of financial skin in the game may contribute to divers' lack of rigorous health surveillance or accurate self-assessment. So the attitude may be, "If anything happens, I'm covered."