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.
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.
