Going tech - Patent Foramen Ovale (PFO) testing?

[rossh]

This was one of the questions put to the expert panel at the end of the TekUSA conference last weekend.

They were all very much against the screening for PFO in tech divers, and discouraged the getting a screen test. The same recommendation came from a conference on the subject a couple of years ago.

Given that Tech divers are far more likely to encounter DCI issues with existing PFO's. The current approach is to let you experience an accident first, and only then investigate that you are a high risk diver, and then do something to fix it, or banish you to the slow and shallow end of the pool.

There are simple screening tests available that are 90+% accurate. DAN Europe did this on a study of 700(?) divers. This can isolate the problematic patients for further investigation via TEE / TTE, or the diver can decide if its worth the risk to repair the PFO, or change diving style.

 

[ajduplessis]

Tested for PFO, none found. I would agree that testing for PFO is not needed if you dont get bent.... regularly.

Also take note that a PFO can potentially open up when participating in activities such as heavy lifting, squids, coughing to name a few. Age and health also plays a role.

Being PFO free is not necessary a permanent status.....

 

[kensuf]

I'm that guy AJ mentioned that tested negative (TWICE!) on a TEE but tested positive on a TTE. I know another person, who literally wrote a book on CCR cave diving, that had the same experience with the TEE. In my case, I would get bent on mild deco profiles (~20 minutes of deco) but be fine on other profiles. Never had a problem with staying within the NDL's. I attribute my hits partially to humping a set of 104's out of the water while I was bubbling (I hate doing surface deco).

I know people that definitely have PFO's that don't get hits. I know people that don't have PFO's that do get hits. If you're not getting hit, I wouldn't bother getting tested -- the TEE can definitely produce false negatives.

But if you're having problems, get it checked out. I used to get a skin hit once a month (on average) pre-surgery, but I've only had a mild hit once since getting my PFO closed, and I earned it. That dive included a 4 hour run-time, sweating before dive, cold during deco, and as soon as I surfaced I walked a mile through the woods on a hot summer day without stopping for surface deco. According to Shearwater Desktop, I've logged over 700 dives since getting it closed in 2014 with depths ranging as deep as 360' and run-times as long as 7 hours, and only one hit since (knock on wood).

 

[Mouth Breather]

I got bent on most of my tech training dives, each time progressively worse. Insurance paid for the test and the closure, no issues since

BUT it was a very large hole and I have had a history of migranes that my physician used to justify the closure to insurance. The copay/deductible was still in the thousands. Totally worth it

25% of us have a PFO that never closed...a fraction of which will dive...and a fraction of those will have DCS symptoms as a result. I'd wait to see if it's an issue, keeping an eye out for any symptoms.

Good luck!

 

[Stoo]

I agree with some of the other posters. If you have a history of unexplained hits, then you should, but otherwise, it seems like an unnecessary chore.

One of my friends had one patched up a year ago. She would routinely get skin bends following no deco dives or deco dives that were executed conservatively. She even moved to a RB to max out her pO2.

Six weeks after the procedure, she resumed diving. She's been on two trips with me since and lots of weekend dives and had no issues whatsoever.

 

[rjack321]

This was one of the questions put to the expert panel at the end of the TekUSA conference last weekend.

They were all very much against the screening for PFO in tech divers, and discouraged the getting a screen test. The same recommendation came from a conference on the subject a couple of years ago.

Given that Tech divers are far more likely to encounter DCI issues with existing PFO's. The current approach is to let you experience an accident first, and only then investigate that you are a high risk diver, and then do something to fix it, or banish you to the slow and shallow end of the pool.

There are simple screening tests available that are 90+% accurate. DAN Europe did this on a study of 700(?) divers. This can isolate the problematic patients for further investigation via TEE / TTE, or the diver can decide if its worth the risk to repair the PFO, or change diving style.

So with all this added screening... How is one supposed to even "know the risk?" when people dive for years with asymptomatic PFOs, only express symptoms on particular dive profiles, or conversely get bent without a PFO?

I got bent on a fairly aggressive profile with a partial suit flood. There was nothing to suggest I had a PFO but I got tested anyway and was negative on a transcranial Doppler. I still get bent on even modestly aggressive profiles, something I attribute to a posterior C4-5 cervical discectomy in ~2007. But I certainly could have had a false negative from the transcranial Doppler, although symptomatically I know exactly what to expect from not doing enough time (its very repeatable) so I am fairly confident a PFO is not responsible for that.

Nevertheless I am glad to see you have finished your residency in interventional cardiology Ross and are now "bucking the medical establishment" to offer alternative medical advice here.

 

[LiteHedded]

I take all my decompression and medical advice from ross. glad to see him chiming in.

my move is to just be a racehorse and not get bent ever.

 

[Slamfire]

I was at TekDiveUSA last week and on a personal conversation with Dr. Simon Mitchell he did recommend that I get PFO tested. In 10 years of staged decompression dives I've only had one instance of skin bends. But those skin bends were accompanied with an ocular migraine that basically impaired me from driving my car from a ferry lineup into the ferry (my wife drove the car into the ferry). I didn't think much of it because I popped in some ibuprofen and went to sleep for most of the 1hr40mins ferry ride. When the ferry ride was over, I was totally fine -- no more skin rash, no more migraine. I didn't even breathe O2 as it was burried under wet gear and ferry people might give me grief if I pull out an O2 labelled tank.

At the time of my conversation with Dr. Mitchell I told him I could only recall of one other time when I had an ocular migraine right after a dive. Then I remembered another instance. So in all I can only recall 3 migraine episodes right after diving.

I never thought too much about the migraines because I do get them 3 or 4 times a year at times when I have not been diving. Furthermore, my father used to get them frequently and unrelated to diving and one of my siblings gets them very frequently and she doesn't dive at all.

Dr. Mitchell's concern stems from the skin bends appearing with a serious neurological symptom: temporary incapacitating visual disturbance (couldn't drive anymore). He also mentioned that skin bends on the chest and migraines commonly appear on people with PFO.

 

[Patoux01]

Well you do look like an obvious candidate for a PFO, so there's that.

 

[Slamfire]

To me this was a non-issue. I always thought it was a coincidence that all throughout my life I had only two migraines right after diving. And the 3rd one, was just minor skin bends coincidentally showing up with a migraine. The lecture Dr. Mitchell was giving on that day was about DCI Management in the Field. It talked about a detailed protocol that recognized that some cases of DCI might not warrant evacuation from remote locations at a high cost and messing up the expedition for everybody else.

So I presented my case and he said he would have had me evacuated if he had received a call on a satellite phone describing my situation while I was suffering it. I would have thought my case was one not worth having an evacuation. Maybe I was lucky that the thing resolved by itself in less than 2 hours. But this definitely is making me think about my DCI risk from a different angle.