PFO Diagnosis

[TSandM]

The actual pathophysiology of migraine is not completely understood. There are several theories of migraine causation, as enumerated in this article. It is known that vasoconstriction and vasodilatation OCCUR during migraine, but whether either is causative of the pain or not is not clear.

Several studies have shown an association between PFO and migraine, but again, the pathophysiology of this is unknown. As with bubbles and DCS altogether, the coexistence of two phenomena does not always elucidate the causal relationship between them, if any. Immune responses have been postulated to be involved in clinical DCS, and if platelet activation and prostaglandin release are involved in DCS, as they may be in migraines, that might represent a common factor between the two. However, PFO closure has been tried in migraine prevention and did not appear to be particularly useful, as described in this recommendation from the European Headache Federation.

 

[Gene_Hobbs]

Since this has gone on to discuss bubbles and contrast, I thought it might help some folks to 'see' a real clip. I use these in talks.

First, an image of the heart with chambers labeled herehttp://rubicon- foundation.org/graphics/TDS/HeartChambers.jpg


From here, feel free to download the following avi film clips (courtesy David Adams, Duke University Medical Center).

This is a negative bubble study. (no bubbles cross to the left heart) Neg_micros2.avi 10 MB
This is a positive bubble study. (bubbles cross the atrial septal defect to the left heart) 18-51_ASD_+bub.avi 14.9 MB

This is a three dimensional echo clip of a positive study. LAX_LV_bubbs2.AVI 384kb

One interesting example of a cave diving fatality involving a PFO can be found in a talk by Jim Caruso on "The Pathologist's Approach to SCUBA Diving Deaths.".

 

[rakkis]

Thanks, DocVikingo

 

[adjuster-jd]

Doc V -

I'm in Akron, Ohio - just south of Cleveland.

Thanks.

 

[Kendall Raine]

It is a big decision. One of the questions is what an "aggressive" dive is in the context of the medical decision.

I recall at the time I was making my decision discussing the matter with Dr. Campbell(scubadoc) as well as the docs on my medical staff. We finally concluded that lacking some symptomatic indication it just wasn't worth the risk. Especially considering what was involved in the repair surgery.

After all the real question isn't whether to be tested, although that is a significant decision, it is what are you going to do if one is discovered; especially if it is a very small one.

One of the real problems in these kinds of decisions is the lack of data. DCS itself is pretty rare. So, we are really working in the world of personal comfort. No universally correct decision.

It's interesting to note a recent comment by Jarrod Jablonski in the context of David Rhea's really bad hit in the Baltic. He said as many times as he's asked, he can't get any diving physicians to come out and endorse PFO testing even for those doing extreme dives. I'm paraphrasing, but that's the essence of it. Seems the problem is the relationship between PFO and likelihood of a nerological hit isn'ts clear cut as it might seem. Then there's the question of the accuracy of the test. Then there's the issue of pulmonary shunts even though PFO might test negative. Then there's the question of latent PFO (one that tests negative but opens on strain-like climbing a boat ladder) or develops with age. Get the picture? WKPP seems to require a test, but empirical efficacy is not clear. In the case of David, he had apparently tested negative for PFO and took a really bad hit on a dive far less extreme than hundreds of others he's done. JJ believes a shunt to be the culprit but acknowleges that's a guess.

From what I understand, a PFO test, regardless of method, brings with it some risk.

My personal perspective is that evidence of a PFO is a contraindication to exceptional exposures. Lack of evidence is not; however, any assurance against taking a serious neurological hit.

Perhaps Bill Hamilton said it best: "**** happens."

 

[DocVikingo]

Hi adjuster-jd,

Contact the Department of Cardiology at the Cleveland Clinic Foundation; (216) 839-4500

Regards,

DocVikingo

 

[Hemlon]

Migraines related to PTO...anyone?

Anyone...Bueller...anyone?

 

[airsix]

Migraines related to PTO...anyone?

Anyone...Bueller...anyone?

Parent Teacher Organizations? Entirely plausible. Public education is enough to give anyone a headache.

-Ben

 

[TSandM]

Hemlon, did you see my post above?

 

[Hemlon]

Oooppps...I meant to say PFO!