Nitrox question

[PhatD1ver]

Okay, went to my doc yesterday (heart guy) and reported in that I am going diving this weekend. He ran a strip, did a listen, and had me wear a holter for 30 minutes. Then pronounced me 'safe to swim'...

His only request was that I use nitrox for most of my dives, since my target dive depth for the dives this weekend is going to be between 12 meters (40ft) and 30 meters (100ft) (pretty much the sweet spot for nitrox).. my heart palpitations (arrhythmia) tend to be 'exercised induced'. That means that when I get stressed (by a hard swim against a current for example) my O2 levels drop (as they do for everyone), and my respiration rate increases (as it does for everyone).. but in my case, I have these little electrical pathways that begin 'auto accelerating' my heart so to speak in order to get more oxygen to my system...

The doc (who is a diver) thinks that by breathing nitrox, I can maintain a higher partial pressure of O2 in my system, and keep my HR more stable, even under some exercise stress.... it's a theory, so he figures it can't hurt to try it and see how I feel.

For those thinking the doc and I are crazy to let me dive... I have 30 dives in six months, and a few with some pretty exhausting swims against the current where I had to stop and rest a couple minutes, but no problems overall... and I haven't had any of the same issues I have say running when I exercise. His assessment after full heart workups and a stress test is that my condition poses no real danger when I dive as long as I manage it like I would above water..

The one thing he wishes we could do is have me wear the holter over the course of a day with about three dives and see what the effect is... guess I might have to schedule a trip and use my dry suit and see how that goes.... for now, a little experiment with EAN.

I might mention that he has about five experiments he wants to run with me... another one he'd like to try is to see if bottom time increased using EAN in terms of improved SAC on successive dives... his theory is that living in Shanghai, my body develops a resistance to fully utilizing the air in each breath due to pollution, and he believes that give the same dive, depth profile, and using EAN over the course of 3-4 dives that having 'clean air' with additional oxygen in it would clear my lungs successively over those dives. Poor doctors that think too much.

Any thoughts?

 

[TracyN]

I don't think his theories are very sound. Might want to get a second opinion.

 

[Dirty-Dog]

I think a lot would depend on exactly what your arrhythmia is.
But if it's caused by a lack of oxygen to the tissues, then I question if you're really safe to dive.

 

[TMHeimer]

No medical advice from me. Logically, why not try some kind of exercise on land while breathing nitrox and see how you feel? Maybe a stationary bike, or even swimming in a pool on the surface. With someone keeping an eye on you, it would seem less risky than diving.

 

[fbk]

Yeah I don't think I'd want to put any "theories" about preventing myself from having a heart attack to the test while underwater, or even on the surface for that matter.

 

[azstinger11]

Have you talked to the folks at DAN? They are probably the best experts when it comes to dive physiology. Link email or phone call options available.

 

[PhatD1ver]

I think a lot would depend on exactly what your arrhythmia is.
But if it's caused by a lack of oxygen to the tissues, then I question if you're really safe to dive.

Been dealing with it for years, once it became a little more noticeable, we reviewed EKGs from my flight physicals in the Army and found the same thing... I've been carrying it around a long time, but the introduction of exercise has made it more noticeable..

I didn't say my tissues were dying from lack of oxygen, all people when they exercise get hypoxic, that's why we breath faster, so more oxygen is utilized to support us... in my instance, my heart tends to react wildly and alternate electrical pathways go off when this happens, for the same reasons.

That being said, I've been tested, retested, and tested again for four years. Nothing I do (including diving) is going to give me a heart attack as a result of this condition, and one of the control methods for this type of arrhythmia is actually the valsalva. When I experience the little butterflies in my chest, or the monkey scratching to get out (when I'm in full exercise mode)... all it takes is to STOP doing whatever I'm doing (running, biking, etc) and do a nice controlled valsalva and it 'resets' my heart so to speak.

Again, the doc here is new to me, but been around for a while, and the doc in the US confirmed that I'm at no risk of heart attack, but that I need to continue to manage this like I have..

As to if the nitrox helps or not? don't know, but I do know it will help with improving my no-fly time on a tight weekend dive schedule, and, the profile fits, and for six dives it's going to cost me $60 extra, I can live with it, and after I've done it, I'll know if it doesn't anything for me. Got nothing to lose really.

 

[Steve_C]

I would use the Nitrox AND avoid potentially high exertion dives. Sometimes you can stop the exertion and sometimes you are stuck with it. For example, if dealing with a down current it is not the optimal time to stop and rest.

How does it affect your being a buddy? Is it only physical stress or can mental stress like during a rescue bring it on?

 

[sphyrnidus]

Well Trent, to ask this question here will never get you a relevant answer. All the internet doctors can't tell you what is good for you. Btw is the Holter able to withstand pressures of up to 4 bar and if it dies, is it at your expense? Medical machines don't come cheap.
There is also a medical sub forum where doctors give advice. Maybe it would be better to ask your question there. Btw while a doc. I'm not a cardiologist so I won't bother you with my opinion

 

[wspalding]

I don't think this is a SB question, but is one that should be saved for a physician with a specialty in dive medicine and cardiology.