• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Patent Foramen Ovale and freediving

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Well-Known Member
Jul 5, 2004
Lately there's been a lot of discussion about Patent Foramen Ovale in relation to decompression sickness in scuba diving. I'm not going to try to explain it (read the links:here or here ). Basically it's a birth defect of the heart found in (some say) as many as 30% of the population. It is usually unnoticable and does not cause any problems but has been linked to the risk of getting DCS.

What I found disturbing is the fact, that the opening may be enlarged due to overpressure of the lungs. In the article they refer to the Valsalva manuever, but in wouldn't packing have this effect also? In fact, would it not be much more dramatic? In really deep and frequent freedives, with heavy packing involved, it would make sense to me that the kind of paradoxical embolism of gas bubbles described in the article would be possible.

It also says people with PFO are more likely to accumulate fluid in their lungs. Could there be some relation to the risk of getting "squeezed"? Does having PFO partially explain the blood shift? How would this effect freediving performance and risks?

I find this interesting as estimates of PFO in adults vary from 10% to 30%. With my limited understanding it seems quite alarming, so please go ahead and prove me wrong! :)

At least one more reason to learn the Frenzel.
Frenzel wouldn't help much. You are still putting on the pressure

I had a PFO check last year - partly because of a bend and partly because my doc recommended it because of the freediving.

The check is about £200 and fairly harmless so if you ever get the option, its worth doing

DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing


ISSN 1469-865X | Copyright © 1996 - 2024 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Ocean Advocacy and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.