Permeable oval foramen

[Tomeck]

The permeable oval foramen is a counter-indication for the diving, because there is a risk of decompression accident?

 

[TSandM]

Patent foramen ovale (a communication between the atria of the heart) has been implicated as a causative agent in neurological DCS. However, as THIS article on the DAN website states, the connection is far from clear. From my understanding of the literature at present, it would be too strong to say that a PFO is a contraindication to diving. After all, given the prevalence of PFO in the general population, it is likely that there are a great many people with PFOs out there diving safely. It is certainly not reasonable to have everyone contemplating scuba diving undergo screening for PFO, or PFO closure. Those doing more aggressive (technical) dives might think about it, and it's probably not unreasonable to screen people who have had an "undeserved" DCS episode, although I'm not even sure the literature supports that.

Additional links:

http://scuba-doc.com/pfo.htm
http://www.uksdmc.co.uk/newsletters/Newsletter 02-01.htm
http://www.annals.org/cgi/reprint/134/1/21.pdf

In addition, a search of the Rubicon Research archives will produce more reading material than you probably want!

 

[Tomeck]

Patent foramen ovale (a communication between the atria of the heart) has been implicated as a causative agent in neurological DCS. However, as THIS article on the DAN website states, the connection is far from clear. From my understanding of the literature at present, it would be too strong to say that a PFO is a contraindication to diving. After all, given the prevalence of PFO in the general population, it is likely that there are a great many people with PFOs out there diving safely. It is certainly not reasonable to have everyone contemplating scuba diving undergo screening for PFO, or PFO closure. Those doing more aggressive (technical) dives might think about it, and it's probably not unreasonable to screen people who have had an "undeserved" DCS episode, although I'm not even sure the literature supports that.

Additional links:

http://scuba-doc.com/pfo.htm
http://www.uksdmc.co.uk/newsletters/Newsletter 02-01.htm
http://www.annals.org/cgi/reprint/134/1/21.pdf

In addition, a search of the Rubicon Research archives will produce more reading material than you probably want!

Thank you very much for links.

I believe in United States, a PFO isn't contraindication, but in France, PFO is a definitive contraindiction, if you have a first decompression illness and it is necessary that a PFO is closed by surgeons so that the doctor accepts the end of definitive contraindication.

 

[knotical]

I believe in United States, a PFO isn't contraindication

According to the RSTC Medical Statement and associated Guidelines for Diver’s Physical Examination, which is used by several of the major recreational scuba training agencies in the United States and elsewhere, it is a severe risk.
See at: http://www.wrstc.com/downloads/RSTCMedStatementGeneric.pdf

Severe Risks
Venous emboli, commonly produced during decompression, may cross major intracardiac right-to-left shunts and enter the cerebral or spinal cord circulations causing neurological decompression illness.

Part of the problem is that most people don’t know whether they have a PFO.

 

[Tomeck]

According to the RSTC Medical Statement and associated Guidelines for Diver’s Physical Examination, which is used by several of the major recreational scuba training agencies in the United States and elsewhere, it is a severe risk.
See at: http://www.wrstc.com/downloads/RSTCMedStatementGeneric.pdf

Part of the problem is that most people don’t know whether they have a PFO.

OK, I see, but DAN say PFO isn't necessary a contraindiction, it's difficult to know who is right.

 

[knotical]

OK, I see, but DAN say PFO isn't necessary a contraindiction, it's difficult to know who is right.

The RSTC guidance for physicals simply states that if a patient is known to have a PFO, they are at risk of severe consequences. They do not address probabilities. As with all risks, both should be considered.

 

[Dr. Doug Ebersole]

As a cardiologist who closes PFOs (patent foramen ovale) on a regular basis, having a PFO is definitely NOT an absolute contraindication to diving. Approximately 25% of the population (and therefore probably 25% of divers) have a PFO. The issue in diving is the possibility of venous gas bubbles that would otherwise be filtered by the lungs getting into the arterial circulation and causing an DCS/AGE.

The current recommendation in the cardiology community would be that having a PFO probably does increase the risk of DCS/AGE about two fold over the general population. However, given the extremely low ABSOLUTE risk of DCS in diving, two times a very small number is still a very small number. However, should someone suffer an "undeserved hit", they should strongly consider PFO closure which can usually be done percutaneously these days and does not require surgery.

Hope this is helpful.

Doug

 

[D_B]

Good posts TS&M, Doug
Most do not know about PFO's , how prevalent they could be in the population in general, or that they are a possible explanation for an "undeserved hit".. Thanks

 

[Gene_Hobbs]

In addition, a search of the Rubicon Research archives will produce more reading material than you probably want!

Thanks again Lynne!

It is also worth adding Saturation's page to a list of reading material (found here) as well as PubMed search results.

Dave Southerland also addresses PFO's on profiles likely to produce high bubble loads:

Southerland DG. Medical Fitness at 300 FSW. In: Lang, MA and Smith, NE (eds.). Proceedings of Advanced Scientific Diving Workshop: February 23-24, 2006, Smithsonian Institution, Washington, DC.
RRR ID: 4659

 

[Tomeck]

As a cardiologist who closes PFOs (patent foramen ovale) on a regular basis, having a PFO is definitely NOT an absolute contraindication to diving. Approximately 25% of the population (and therefore probably 25% of divers) have a PFO. The issue in diving is the possibility of venous gas bubbles that would otherwise be filtered by the lungs getting into the arterial circulation and causing an DCS/AGE.

The current recommendation in the cardiology community would be that having a PFO probably does increase the risk of DCS/AGE about two fold over the general population. However, given the extremely low ABSOLUTE risk of DCS in diving, two times a very small number is still a very small number. However, should someone suffer an "undeserved hit", they should strongly consider PFO closure which can usually be done percutaneously these days and does not require surgery.

Hope this is helpful.

Doug

Very good post !

Why we call "Patent", I think "patent" is an intellectual property right covering an invention?