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Blood pressure trends during apnea

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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glennv

hybrid lifeform
Nov 28, 2002
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Lately i have started experimenting with the use of a heartrate monitor to visualise the dive reflex during a static atempt.
Very interesting to see how the heartrate suddenly drops like a brick round about the struggle phase. Especialy suprised i was about how low it can get. Always heard about it , but not untill you realy see it it comes out of the realm of something theoretical to something in your face.
This made me wonder however, if there is a clear trend in the bloodpressure as well and how this evolves during a static (or other ) attempt.
I can understand an increase at the start during a final big breath and at the end a sudden drop when comming up, but how about in between and how do we translate this trend in physiological events.

Also does bloodpressure relate to how hard you feel your heart beating. Sometimes it feels like it comes out of my chest , while on other days or other phases within an attempt it is not that pressent.
 
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Here is a graphic of blood pressure trends of Enzo Maiorca (A) and his daughter Rossana (B) during an experiment in a hyperbaric chamber
 

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Thanks. So on first glance it looks like, similair to the heartrate, the BP also drops after an initial rise in the beginning of the dive en continues to drop untill the end.
I wonder why ? Initialy i would think that vasoconstriction compared with a low heartrate would make it necessary to make each beat count e.g. up the pressure.
(although Enzo's heartrate seems to remain almost stable, but then again this type of graph is a bit hard to read compared to the single line graphs. Or maybe this is due to the fact that it is a dry dive e.g. no real dive reflex. Seen similair things with dry static compaired to wet, where the heartrate does not drop as dramaticaly)
 
Hi Glenn,
The BP graph has 2 components Systolic and Dyastolic, it was measured drectly from an arterial line, and were wet dives, because the chamber was filled. They get immersed as the dive begin.
In the graphic B at the surface, before the breath-hold, the BP is around 200/100 which is very high, as the dive begin there is a systolic peak, and if you look on Enzo's graphic the peak for him was almost 300, which is extremely high, it goes down but never is below "normal", and persists high some minutes after surfacing.
The EKG is from pressure pulse, I will post the heart rate of this inmersion later
 
Heart Rate

This are the graphics: E= Enzo, P= Patricia and R=Rossana
Black boxes= Heart rate, white boxes=depht
 

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Wow, I never knew the effects were that profound. The systolic peak is remarkable enough, but the differential between the systolic and diastolic is amazing. Do these kinds of events pose any risk of injury in fine capillaries in the "core" organs (i.e. the organs that get favored during a blood shift)?
 
Ah thanks. I misinterpreted the graphs (am not medically trained)
Looks like the bloodpressure does not follow the same pattern as the heartrate, which can be extreme. I also did not realise how fast the rate can drop. In a dynamic i did today it dropped from a whopping 100 bpm to 50 in 14 seconds. Amazing....

I do share the concern with Pezman. Small capilaries in the brain, can't they get damaged by this ?
 
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Also , is the speed of the heartrate drop an indication of adaptation. If you look at enzo's graph , his rate drop much faster then of the 2 girls.
 
Capillars can support a lot of stress, I don't know of any serious report on this. But I don't recommend this sport to any person with High Blood pressure or cardiac problems.
I think (and is my personal opinion) that this can contribute to pulmonary edema in freedivers, mainly from rupture in pulmonary capillars. But this is so infrecuent, that I don't think is a real problem.
I don't know what is more important, how fast the slow heart rate (bardycardia) comes, or how deep it is. In the graphs both Rossana and Patricia get the bradycardia slower than their father, but it was deeper.
He was older, and with the age we lost some of our diving reflex.
But looking people like Annabel, this is questionable.
 
If pulmonary edema occurs in freedivers it would not necessarily be a consequence of capillary rupture. An increase in pulmonary blood pressure can result in an increase in capillary hydrostatic pressure sufficent to cause accumulation of fluid within the alveolar spaces of the lungs.

lee
 
In -94 I participated in a research about diving response. I did a max apnea of 4' with my face in 10C water. My heartrate went down to 40 bpm. My bloodpressure did however rise with increasing contractions and was very high at the end of the apnea! They said this could cause ruptures of capillaries in the brain!

The speed and amount of the heartrate drop was found to be linked to adaptation and increased diving response. The heartrate dropped 45-50% in average in freedivers and 20-25% in untrained persons.
 
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Thanks Fenixxx, nice articles. Gives some more insight in this subject, which is obviously not clear yet. Untill now my believe has always been that apnea training has a positive effect on several aspects of the human body (instead of beeing a dangerous sport which causes brain damage , which most people think and give me back as a reply). Untill more light is put on this issue of possible brain capilary damage due to high blood pressure, i have lost my amunition in the pro/contra apnea discussions with my friends. :waterwork

If anybody has some other research results or interesting links about this subject , feel free to share it with us
 
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Hi Glenn,
This is all theoretical. How many brain bleeding will happen in a competition if this was true, there is a big difference in physiologic hypertension and pathological hypertension. Those are bouts of hypertension, but it returns to normal.
Fein,
That increase of hydrostatic pressure can cause stress failure of pulmonary capillars, is the same mechanism of high altitude pulmonary edema. The severe hypoxia induces vasoconstriction.
 
what relation is there...

Of course there is a relationship with the possibility of B.O., but apart from the fact that it might be interesting to study this topic,
I don't see any direct relation between blood pressure and performance.....
 
Originally posted by glennv
Thanks. So on first glance it looks like, similair to the heartrate, the BP also drops after an initial rise in the beginning of the dive en continues to drop untill the end.
I wonder why ? Initialy i would think that vasoconstriction compared with a low heartrate would make it necessary to make each beat count e.g. up the pressure.
(although Enzo's heartrate seems to remain almost stable, but then again this type of graph is a bit hard to read compared to the single line graphs. Or maybe this is due to the fact that it is a dry dive e.g. no real dive reflex. Seen similair things with dry static compaired to wet, where the heartrate does not drop as dramaticaly)
 
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