A Better Heart-Check Tool than a Stress Test?

In our May article "Heart Health in Older Divers," we reported on a 65-year-old diver, who rarely exercised and never visited a doctor, dying minutes after starting a dive in the Galapagos. That story sparked many older divers to ask what they need to do to prevent something similar happening to them. Should they go in for a stress test before a dive trip? Carry a portable automated external defibrillator (AED) with them? During our research, we learned there are no clear guidelines for whether older divers should have regular stress tests, and no mandates for dive boats to have AEDs onboard. In fact, the American College of Physicians (ACP) published new guidelines warning people against routine cardiac testing, saying it hasn't been shown to improve patient outcomes, and it can actually lead to potential harms. Divers Alert Network (DAN) says it supports those new guidelines, but are they considering the stress that divers, in particular older divers, may face in tough conditions?.

When it comes to divers, Undercurrent subscriber Bruce Hoyle, M.D. (Newport Beach, CA) isn't on board with the ACP's guidelines.He told us that while he generally agrees with the ACP recommendations against routine testing of asymptomatic individuals,"this is a recommendation for the general American population. Divers traveling to remote parts of the world with limited medical services are a special subset. Perhaps DAN should add some recommendations to the ones they already have regarding diving after a heart attack."

Hoyle is right: Diving is a stressful situation and the ACP does not speak to that. Should DAN support that conservative view when its audience of older divers is moving into high-stress situations? Even if they have not had heart attacks, shouldn't older divers consider taking a stress test before diving in remote places like the Galapagos or Cocos Island?

Petar DeNoble, DAN's vice president of mission, whom we quoted in the May issue, said, "DAN is not in a position to support or to contest the ACP guidelines, but rather, follows it. While there is no recommendation to test asymptomatic people just because of their age, the risks should be evaluated and selective testing done. "

Jim Chimiak, DAN's medical director, concurs. "The confusion occurs because the ACP guidelines also support a regular physical examination by one's primary physician, diet and exercise. It is very likely that [the dead diver's] physician would have become alarmed if he had come to him prior to his remote vacation where he planned rigorous exercise. In addition, a regular exercise program may have demonstrated increasing difficulty with any sustained vigorous exercise, and would have led him to urgent follow-up. A graduated program working up to diving in remote locations is a good idea that incorporates an ever-increasing level of physical exercise. But again, whenever a problem is suspected, more detailed clinical investigation is warranted, especially if future plans include visiting remote locations with limited or no immediate medical services." In short, go visit your doctor before you go on a dive trip overseas.

Like health, diving is a lot about prevention methods. "The inside of a scuba tank needs periodic inspection; the same thing applies to the heart," says Hoyle. That's why he is a proponent of a coronary calcium scan, which uses a special X-ray test called computed tomography to check for heart disease in an early stage and determine how severe it is. "It's a simple test available for $200 or less and will tell you the plaque load in your coronary arteries compared to other men and women of the same age," says Hoyle. "Being in the 90th percentile means 90 percent of people your age have less plaque than you. You might still pass a cardiac stress test with this score incidentally, but you would now be on the radar for your doctor to be aggressive with diet, exercise, medications, close follow-up and perhaps recommendations against diving in remote locations.

" Once you have a positive stress test, you already have significant coronary disease by definition. A coronary calcium scan can tell you years before a positive stress test that you are headed in that direction, so that you can do some kind of intervention. To spend $150 every couple of years to know the status of your heart is a bargain."