Hmm...I'm no cardiologist but I have had this discussion with my cardiologist before. I have had stress-induced arrhythmia, I suffer from hypercholestrolemia, mild hypertension and worst still, I am allergic to any Aspirin-based medication.  So he ran by a few scenarios with me to scare me be it an open-heart bypass, or angioplasty.

Although Angioplasty is a non-invasive procedure and can be done on an outpatient basis, it must be established that the diver has reasonable tolerance for strainuous activities. The most important thing is to NOT develop any ischemia during the exercise (usually the stress test done on treadmills).  The diver should also be cleared from any left ventricular dysfunction.

I would suggest for you to in turn suggest to your friend to go back to his cardiologist for an opinion.  I do know of people who have done Angioplasty whom have gone back to diving.  Tell him to be safe with his new lease of life. He's living on bonus time.

Maybe Bones and DiveDoc would be able to elaborate further on this, or correct me where I am wrong.

I found and bookmarked this particular site sometime back. Please note this is year 2000 material, and as always, referring to an actual cardiologist is the way to go.. Alas, not many of them actually know enough about diving.

http://www.cardiologytoday.com/200009/frameset.asp?article=FinalBeat.asp

Pasted here in text form;

What you should know before you let a patient scuba dive
September 2000

PHILADELPHIA — A tragic experience with an aspiring scuba diver showed Alfred Bove, MD PhD, how little doctors know about the sport.
 
Bove, a cardiologist and associate dean of Temple University School of Medicine, had been teaching scuba diving classes at the YMCA, when a male student enrolled five weeks after a myocardial infarction (MI). “I told him I didn’t want him in my course because it was far too strenuous. But he said his doctor told him it was all right. Fortunately, the student soon left the course on my advice,” Bove said.

Shortly thereafter, the man died after a second MI.

“Most physicians don’t understand that scuba diving is not basket weaving. Obviously with ice hockey or basketball there’s physical stress, but the same is true for scuba diving. Another issue is injuries. Even the lay[person] understands that if you’re skiing and you smack into a tree at 100 mph you’re probably not going to walk away. However, physicians often don’t understand that if you hold your breath and swim up too fast, you’re going to rupture a lung,” Bove said.

Bove’s expertise in scuba diving-related medicine comes from 35 years as an undersea medical officer for the U.S. Navy. He now teaches undersea medicine courses at Temple University, writes a monthly medical column for a leading scuba diving trade magazine, and has authored two textbooks on diving medicine.

A certified scuba diver, Bove recently retired from reserve duty with the Navy and consults for the military and for the commerical diving industry in the United States.

“While there are about 10,000 divers and submariners in the Navy, and about 5,000 commercial divers, those numbers don’t compare to the two to four million sport scuba divers who have no regular diving medicine specialist. There are a lot of cardiovascular issues that come up. You can die suddenly at the bottom of the ocean, the same way you can die suddenly from over-exertion while playing tennis,” said Bove.

In an interview with Cardiology Today, Bove explained what cardiologists should know before approving a patient for scuba training.

What drugs should I watch for? Calcium antagonists at moderate doses may cause excessively low blood pressure. Relaxed blood vessels cannot respond to a postural change caused by standing after sitting down for a long period. The sudden drop in blood pressure may cause dizziness or even a blackout.

“This would not be appreciated on a dive boat, where one episode of a diver passing out can ruin the day for everyone. Patients who feel dizzy when getting up quickly as a result of a calcium antagonist should not dive,” said Bove.

Beta-blockers have many side effects, but only a few limit a patient’s ability to dive. Patients who are on beta-blockers and also have asthma should not dive, because the combination can result in wheezing. Cold sensitivity brought on by beta-blockers will not be a problem if diving in warm water. Other side effects like impotence, slight dulling of mental function and reduced exercise performance do not impair a recreational dive.

ACE inhibitors present no problems with diving.

Diuretics will cause no long-term problems for a diver. However, since diuretics remove salt and water from the body, the effect combined with sweating on a hot day could cause excessive dehydration. “Patients should skip their diuretic on a dive day,” said Bove.

Can a patient with a pacemaker dive? It depends on the case, Bove said, but the pacemaker itself can resist pressures that are present in up to 130 feet of water — the limit for sport diving.

Should I prohibit a patient with atrial fibrillation (AF) from diving? When divers are submerged, there is a shift of blood into the upper body from the legs. The added blood in the heart stretches the atria, making them more prone to fibrillation. However, if patients are treated with proper medications and trained to respond to rapid heart rate, then the presence of AF alone will not make diving dangerous.

If the patient is being treated with an anticoagulant for AF, Bove said patients may want to forgo diving due to bleeding concerns. “One concern for excess bleeding is injury caused by an ear or sinus squeeze at deep depths. Bleeding into the middle ear from an ear squeeze can cause a severe middle ear infection due to trapped blood. With good diving technique squeeze can be prevented. AF does not mean the end of a sport diving career. In the absence of severe heart problems, use of medication to control heart rate and anticoagulation when indicated will not prevent diving. Caution is needed to dive safely.”

 What about coronary artery disease? Bove considers MI to be the main cause of sudden death while diving; therefore, CAD patients with demonstrated ischemia or angina should not dive. Patients who have heart damage from an MI or have heart failure should not dive.

“Many people have returned to diving after angioplasty — the key is the ability to exercise safely. Because the diving population is getting older (we started teaching sport diving in the 1950s) and the incidence of coronary disease increases with age, it is inevitable that divers will be asking about returning to diving after having angioplasty or a stent,” Bove said.

Aspiring divers should wait six months after a procedure to limit the risk of restenosis, after which time they should undergo a stress test. Stress tests should continue annually or biannually depending on the severity of the original blockage.

“For safe diving I recommend an exercise capacity of about 13 mets or stage 4 on a Bruce exercise protocol. Although some people consider this to be a high workload, it covers all the demands of diving, which might include swimming in a current or assisting another diver. Usual sport diving in temperate waters with minimal current does not require this level of exercise but the reserve capacity is needed for safety,” he said.

What if my patient has mitral valve prolapse? Bove said this condition alone is not a problem, but the key again is exercise capacity. If exercise induces rapid heartbeat, diving should not be done. Leaky heart valves should not present a problem unless the leak somehow compromises heart function. The same principal is true for replacement valves.

“Prolapse of the mitral valve is a common enough finding in normal people that it cannot be considered a disease and it is not a contraindication to diving. In some people, accompanying heart problems can limit diving, but most of the associated problems can be treated with medication, and diving can be done safely,” said Bove.[/i]