Heart of the Matter

By Samuel Shelanski, M.D.

The scuba doc answers all your questions
about diving and heart disease.

Risk Factors

Dozens of you have written to ask whether it's OK to continue diving after being diagnosed with hypertension and heart disease. While I can't answer every letter in print, I have tried to address most of your concerns in my answers to these letters.

QUESTION:
I am 59 years old and recently certified. I have a history of mild hypertension. Is there a level of recreational diving at which even us oldies can participate without too much concern? The sort of diving that I tend to do is on shallow reefs at about 35 feet, for no more than 40 minutes.

I understand that if I wanted to dive to the limits of the tables, I would need frequent checkups and would be taking a real risk. But I had assumed that my "trivial" dives were putting me at no greater risk than snorkeling or jogging.

Peter G. Smith
via e-mail

ANSWER:
Two separate issues raised in your letter need to be addressed. The first of these is your hypertension, and the second concerns what you call "trivial" dives.

Hypertension affects whether a person can dive because it is a risk factor for coronary artery disease. For this reason, I recommend that all hypertensives, and anyone over the age of 45, have annual physicals to ensure their fitness to dive. In addition, anyone with two or more of the cardiac risk factors described in "Risk Factors To Learn by Heart" (see page 99) should have an annual exercise stress test to make sure that they can exercise to a sufficiently high level to participate safely in diving. An acceptable, or satisfactory, result on a treadmill exercise stress test means that the person is able to complete at least six minutes of the standard Bruce protocol without chest discomfort or significant electrocardiographic (EKG) changes that would indicate coronary artery disease.

The type of medication prescribed to treat your hypertension must be factored into the decision. Of particular concern is the class of medications known as beta-blockers, which can limit your ability to achieve the level of conditioning necessary in an emergency situation, and diuretics, which can dehydrate you and increase the risk of DCS.

Another concern is the type of diving you do. While it is certainly true that the type of diving you describe is less strenuous, and probably less dangerous than diving in cold water or swift currents, there is still some risk. Every dive must be considered potentially strenuous. You must have a sufficient amount of physical reserve beyond what the planned dive requires in order to cope with unexpected situations or changing environmental conditions. For this reason, I require divers to demonstrate that their hearts can handle more than the minimum amount of necessary exercise before I clear them for diving.

See your doctor, have a physical and an exercise stress test, and if you're cleared to dive, continue diving as you have.

QUESTION:
I had cardiac bypass surgery eight months ago and feel fine. Is there any reason why I shouldn't dive?

Bob Penko
Euclid, Ohio

ANSWER:
Heeding a few caveats, you can still dive after cardiac surgery, though the decision depends largely upon the extent of the coronary artery disease and the amount of damage to your heart prior to surgery. A person diagnosed with heart disease after experiencing chest pains while running is far more likely to be a suitable post-op diving candidate than someone whose first symptom was a massive heart attack that destroyed a large amount of heart muscle.

After your surgeon declares you fit to resume full activities, take an exercise stress test to ensure that you are capable of achieving a satisfactory exercise level to participate safely in diving. If you're able to exercise well, then there's no reason that you can't resume, or begin, scuba diving.

QUESTION:
I recently underwent open-heart surgery for aortic regurgitation and had my aortic valve replaced. I am 40 years old and am an advanced diver. My surgeon told me that I can return to my normal activities; however, although he was not personally opposed to my diving, he recommended that I consult someone more knowledgeable.

I do not have any medical problems other than the valve replacement. The only medication that I take is 7.5 mg of Coumadin daily. Can I dive?

Mark Nevins
via e-mail

ANSWER:
Many of the issues that apply to cardiac bypass surgery also apply to you. However, there are certain aspects of your surgery that complicate the matter.

There are no absolute contraindications to diving with a prosthetic valve. However, there is the possibility that the turbulent blood flow across the replaced valve may promote bubble formation on ascent - putting you at risk for a small stroke if these bubbles travel to your brain.

Of greater concern in your case is the fact that you're on Coumadin, a blood thinner. I assume that prior to your surgery, your surgeon discussed the pros and cons of the two main types of replacement valves, artificial and porcine. Given your age, an artificial prosthetic valve is clearly the best choice, as porcine valves need to be replaced every seven to 10 years, but it means you must take Coumadin.

The problem with diving on Coumadin stems from the potentially serious bleeds that can occur from ear or sinus squeeze or any other barotrauma. A ruptured small blood vessel can result in a significant hemorrhage.

Because of this, I must advise against your diving again. I realize that this is terrible news, but the potential risks to your health far outweigh the benefits.

Questions for Dr. Shelanski should be addressed to:
RSD/Dive Medicine
6600 Abercorn St., Suite 208
Savannah, GA 31405

E-mail:
RSDmgzn@aol.com