Cold Water Swimming and Atrial Fibrillation

Salty_PhilSalty_Phil Member
edited May 2014 in General Discussion
Hello and Happy New Year to everyone. Has anyone on this forum experienced or have any knowledge of Atrial Fibrillation linked to cold water immersion. I have been sea swimming for around 4 years and winter swimming for the past two years. In December of this year I went for at my local beach here in Ireland. The water temp in the harbour was reading 6.8 deg C and outside the harbour in the bay it was 7.6 deg C on my digital dipper so it was pretty cold but not arctic conditions by any stretch of the imagination. It didn’t feel too bad and I got in fairly slowly and done the usual couple minutes of head up breaststroke before I started swimming front crawl. I swam for a little under 1k and got out about 15mins later but I couldn’t settle into my stroke/breathing during the swim. I went into the sauna to re-warm and my heart went into cardiac arrhythmia (Atrial Fibrillation). I was admitted to the Coronary Care Unit in the local hospital and my heart stayed in fibrillation for 2 days before reverting back to normal sinus rhythm under medication (luckily as they were due to stop and re-start my heart the next morning which I didn’t like the sound of!). The doctors spent the next two days monitoring me and carrying out tests but all was clear and my heart was found to be healthy with no apparent underlying issues and I have since been pool swimming with no problems.
Has anyone else on the marathon swimmers forum has had experience with A-fib? I’m not sure what caused the A-fib episode this time round as I have winter swum many times and this has never happened before. I’m 39 years old and A-fib is usually an issue for 70 and 80 year olds so I would like to get to the bottom of it if I can. The only thing I can think of that was different with this swim is that I re-warmed in the sauna which I never normally do and I was recovering from a chest infection at the time. I’m not sure if I went into A-fib in the sauna with the sudden temp change or upon entering the sea but it would be good to hear if anyone else has any experience with this. I don’t want have to give up winter swimming but I’m not keen to have a repeat episode. Just not sure if this is a once off or if I’m going to be pre-disposed to A-fib and might have to limit myself to dips in 12 degree plus water temps.

Cheers

Phil
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Comments

  • DavidDavid Member
    edited January 2014
    Hi Phil

    Sorry to read about your problem with Atrial Fibrillation. Its fascinating to read your account but I guess not so much fun to experience. I am glad you seem to have good health care and the doctors have helped you.
    The Temperature of 6.8 deg C is quite cold! I say quite with a smile on my face because I am currently struggling to maintain my training because the pool and sea temperatures are hovering at 28 deg C. I was wishing for colder water yesterday and after an hour of fast sets I was dehydrated! I had to drink two liters of water before I started to feel normal again. I dream of swimming in 12 to 18 deg C water :)
    I am sorry I cant help you further. Have you researched it using Google? There's so much out there I am sure someone else has the answer you need. For a start you might like to read the following. http://www.medicalnewstoday.com/info/atrial-fibrillation/causes-of-atrial-fibrillation.php

    Good luck
    miklcct
  • It's the sauna.... while we in SF adore our sauna , after 35 some years of OWS, I am finding anecdotal ( ie personal) evidence that that lovely sauna is what #1- leads people to think they can stay in longer than they would normally because* there's a sauna I'll warm up there" and #2- that rewarming too quickly kicks them into fainting or in your case atriall fib.
    I am no expert, nor am I a doctor but I bet if you had just shivered you'd be fine.
    Again, anecdotal.. I know there is research out there on the cold and the heart but not so much on the rewarming process and the heart.
    Tracy_Clark
  • Thanks for the comments. I had a good read around on google and a chest infection can be a trigger for a fib but there is very little on the net about the cold water or re-warming and a fib. I'm off to the heart specialist in Galway tomorrow for my last round of tests and if I get the all clear and they can't find any underlying condition i'll be putting it down to a combination of the chest infection and re-warming in the sauna.
    Had the heart rate up in the 170's during my pool sesh this morning with no problems so hopefully all is okay and its just a one off.
  • molly1205molly1205 Lincoln, NebraskaSenior Member
    What a scare you had! I think Suzie's response makes sense - though I'm no doctor. Hopefully your specialist will give you the all clear to get back to swimming and you can enjoy the cold water, just with a slower rewarming process afterward. Let us know how things go!

    Molly Nance, Lincoln, Nebraska

  • DanSimonelliDanSimonelli San Diego CASenior Member
    I agree with Suzie, anecdotally ;-)

    I think it's the quick rewarming, vasodilation of the blood vessels outside the core, cooling the blood as it circulates through the cold extremities and then back to the heart!

    I don't like jumping in a jacuzzi right after...I think it's better to bundle up, walk around and shiver...that seems to do the trick for me, anecdotally :-)
  • emkhowleyemkhowley Boston, MACharter Member
    Hi @salty_phil Sorry to hear about your bad episode. That is indeed terrifying, and I hope that the recovery is going well and that you never have to deal with that again.

    I am not a doctor, nor do I play one on TV, but I am an ice swimmer who dabbles in hypothermia from time to time, and I have just recently completed research for an article I've written about the condition. In my research I turned up some valuable resources that could help explain what happened with you. Based on this research, I would hazard a guess that you suffered the consequences of afterdrop, which was exacerbated by the sauna. I'm basing this theory on a paper I found online called "THERMAL AND CARDIOVASCULAR CHANGES DURING THREE METHODS OF RESUSCITATION FROM MILD HYPOTHERMIA" by J.S. Hayward, J.D. Eckers and D. Kemna. Link: http://www.hypothermia.org/Hypothermia_Ed_pdf/3-Methods-Rewarming.pdf

    In the paper, the authors test three methods of rearming after inducing hypothermia in test subjects. Patients who were submerged in a warm bath were most susceptible to severe afterdrop, whereas patients who were left to "shiver it out" while bundled in dry blankets had a less-severe afterdrop experience. Patients who were bundled in dry blankets and allowed to inhale warmed air fared the best of the bunch. It's my understanding that the conclusion to be drawn from this is to avoid exposure to extreme heat after becoming even mildly hypothermic, as that facilitates the exchange between warm core blood with cold blood in the extremities and at the skin's surface, which can shock the heart and cause problems. This report has a really dramatic graph (see Figure 4) that shows how the experiment went down and really drove home to me how important it is to exercise extreme care during the rewarming process.

    A similar study published in 2003 excluded the bath but also compared rewarming across three different methods: http://emj.bmj.com/content/22/3/182.abstract?sid=107259a0-eb2f-415d-bb03-42aff9ff26b1

    Another good resource I found was a slim book at the local library titled, "Hypothermia Frostbite and Other Cold Injuries: Prevention, recognition, and prehospital treatment" by
    James A Wilkerson, M.D., Editor; Cameron C Bangs, M.D.; and John S. Hayward, Ph.D.
    It was published by the Mountaineers in 1986.

    I also found this site and its extensive bibliography interesting and useful: https://www.msu.edu/user/manns/Hypothermia.html

    Good luck and STAY SAFE out there everyone!
    bahsan22

    Stop me if you've heard this one...
    A grasshopper walks into a bar...
    https://elainekhowley.com/

  • excellent response @emkhowley . Fascinating stuff for a cold water swimmer. What would you say are the risks of entering cold water when your body is very warm, say, from running? Does this pose a similar risk? Or is it a different process?
  • I LOVE this Elaine... Going to print and post at DC.
  • gregocgregoc Charter Member
    edited January 2014
    I am not a doctor, but I play one on the MSF.

    @gnome4766, the short answer to your question is that it is different. The longer answer from Wikki: "In humans, cold shock response is perhaps the most common cause of death from immersion in very cold water, such as by falling through thin ice. The cold water can cause heart attack due to vasoconstriction, the heart has to work harder to pump the same volume of blood throughout the body. For people with heart disease, this additional workload can cause the heart to go into arrest."

    @Salty_Phil, I recently read a paper that argued that the core afterdrop was not due to cold blood circulating back to the heart, but to a gradient conduction through the tissue.

    Also, it takes temperatures dropping from 35 degrees F (already very hypothermic) down towards 28 degrees F to induce Atrial Fibrillation in a normal heart. You would have to reach core temps that are life threatening before your heart went into AF and I am sure you didn't reach those temps.

    A mild core afterdrop can cause AF if you have underlying heart problems or if your heart was already under stress (such as the chest infection you read about.

    I hope everything checks out clean.
  • Gregoc and emkhowley thanks for your posts really interesting stuff. I went down to the A-fib specialist on Friday thinking I was going to get the all clear but unfortunately it didn't turn out that way. Turns out I have an underlying heart condition which is present in about 2% of the population. I have additional connections at the back of the heart which can cause the normal electrical currents that maintain the heart in sinus rhythm to divert putting the heart into an A-Fib rhythm.

    I quizzed him in relation to cold water swimming/chest infection etc as causing this and his stated that it is not possible to put a 'normal' heart into A-fib under any of these conditions. Either the extra connective tissue is present or its not - its just something that you are born with.

    Good news is though that it's not immediately life threatening and at my age its pretty treatable with a surgical ablation procedure that closes off the additional pathways by forming a scar tissue at their ends.

    What was really interesting though is that in his opinion the A-Fib event is unlikely to have been caused either by entering into the cold water or by re-warming in the sauna. He put it down to the chest infection but believed it would have surfaced eventually anyway. Alcohol, smoking and certain infections seem to be the most common trigger but it can happen just as easily in your sleep as during exercise.

    Still seems like too much of a coincidence to me though. How many cases of patients with a-fib who swim semi-naked in 7 degree C water and re-warm in a sauna straight after would a specialist in Ireland see each year? My guess is none so I'm going to avoid the sauna and sub 10 degree water until I get the op. I guess its the pool for me until May - I just cant face putting a wetsuit on.

    Thanks for the comments.
  • loneswimmerloneswimmer IrelandCharter Member
    @Salty_Phil, that's, well I'm going with good news, insomuch as you have a definite course of treatment and therefore the potential to keep swimming. I think it's been a potentially invaluable discussion for others, and thanks for raising it.

    At 2% possibility, that means we may have sixteen to eighteen forum members who could unknowingly have this condition.

    Best of luck with the op!

    loneswimmer.com

  • danswimsdanswims Portland, ORMember
    A wealth of information on atrial fibrillation here, this post and others on Dr. John's blog.
    http://www.drjohnm.org/2011/04/cw-treating-atrial-fibrillation-in-athletes-tough-choices

    Including some evidence that endurance athletes may have an increased risk.
  • danswimsdanswims Portland, ORMember

    Bump with a link to a book on excessive exercise leading to heart problems, written by a cardiologist who is also an endurance athlete.

    http://www.drjohnm.org/2016/12/graduation-day-from-blogger-to-author/

  • I have had Atrial Fibrilation. It developed slowly and intermitantly, but within a year it had developed into a 24/7 problem. The same cause as Salty Phil, electrical pathways short circuiting the natural heart rythmn making the heart beat like a set of bongo drums being played by a six year old. The fix was a hole in the groin, with a cold wire threaded into the various ateries leading into the heart. The freezing caused a scar inside the arteries which diverted the electrical pathways until the natural beat was restored. I understand it took my doc around 50 scars. The fix was immediate and has never re-occured.

    At the time I was around 45, and had stopped open water swimming, about 5 years earlier (having swam the EC twice) and taken up freediving. Freediving was in its infancy. My swimming experience helped me perform well but I was always 'rubbish' at breath hold. In 2002 in Hawaii I swam 156m dynamic apnea (only 15 meters short of the world record held by Herbert Nitsch). In that comp, Herbert managed 144m. What made it unusual was I could only hold my breath for 5 minutes, whilst he could do 9 minutes. Most of the UK freedive team could hold their breath around 7 minutes, but could not get close to my distance.

    We figured, that my inabilty to breath hold (static, at rest) was affected by the heart beating in AF and therefore burning / wasting O2. But when in dynamic effort, raising my heart rate to around 120bpm from 50bpm, the inefficiency of a misfiring heart rate (at low revs) was erased once a proper heart rate was caused by exercise (although still in breath hold). I guess its a shame I couldn't hold my breath for just 10 seconds more, I might have had a world freedive record.

    Anyway, I had to stop freediving for two years whilst waiting for the surgeon to fix my heart. I then returned to open water swimming. And a couple years ago, did my first ice mile. I am now 59.

    It has been over ten years since my operation and I have never had AF since ( I occasionally have stress induced palpitations, which feel similar).

    It would be interesting to see how Phil is, he should have had his fix by now.

  • I haven't tried since. I was forbidden to do it until well after the opp, so it had been two years since I had a max effort at 5 mins. I had decided to start swimming again instead and needed a clean break from competitive freediving in order not to be tempted to restart. I bet I could do better now (after a year or so training and if the hunger returned). But I also had a problem on one of my last deep dives and came out 100% deaf in my good ear. My hearing returned (to a degree) over the following month, but it made the tinitus much louder. Maybe I am too old now . I need to concentrate on swimming for a few more years yet before I run out of sensible time.

  • mrjamiehintonmrjamiehinton UKNew Member
    edited June 2020

    I came across this thread researching my own AFib and wanted to add my experience in case it helps others. From my own case, I believe there is something very specific about swimming in cool/cold water that can trigger AFib if you have a predisposition for it (either a dilated atrium, low heart rate, extra conductive tissue etc.).

    I'm 36 years old, pretty much a lifetime athlete (swam competitively age 6-19, switching to triathlon in my mid 20's - again racing competitively at a variety of distances). I went into AF aged 34 during gentle shake-out swim 48h before an open water aquathlon I'd be tapering for. I noticed right away since I'm v. attuned to my heart activity - its always been a reliable indicator of fitness/sickness. I wasn't overly concerned as my heart has always fluttered a bit when swimming, though never more than a few seconds and usually when resting between intervals. Anyway, on this occasion I stayed in AFib (no symptoms other than the bongo drum heart, I felt fine) and after 24H I went to A&E and was promptly given a cardioversion, which set me right back to sinus rhythm. They sent me on my way and I actually raced (and won, woop!) the aquathlon the next day.

    Following this I opted to have a bunch of tests/scans which showed no abnormalities other than an enormous left atrium (dilated) and a very low resting HR (38bpm) which are both known substrates for AFib. To test whether or not this could be reversed, I voluntarily took 3 months off training for the first time in 20 odd years. I religiously kept my HR under ~110bpm when working out (I have a max of 175) and, sure enough, after 3 months detraining I shrunk my left atrium from 'Severely Dilated' to 'Very Dilated' and my resting heart rate was up to 50+.

    This was ~3 years ago next month. Since then I've gotten fit again (running rather than swimming/triathlon... but still fairly competitively ~2.5hr marathon). I've run thousands of miles (maybe 5,000+) during this period, from track intervals to tempo runs to 40k mountain runs in all temperatures without a single skipped beat. But... I've also been for precisely 3 swims in this period, and on all 3 occasions (once in a pool, twice open water including last weekend) I have had brief AFib episodes. Never more than 3-5 seconds at a time, but it's fairly clear that, in my case at least, swimming specifically triggers me.

    I  have a few theories of my own... research suggests, for example, that 'splashing cold water on one's face stimulates the vagus nerve' - which could be at play. Also, instinctively I feel like the forced 'unnatural' breathing rhythm when swimming (particularly in cold water) could have an impact. For now I'm having a lot of fun running so I am happy just avoiding swimming... however if/when that changes and I start accumulating other stroke risk factors (advanced age etc.) I'll likely be in the ablation queue!I

    I've been selected recently (through my cardiologist) to be part of a study on AFib in lifetime Athletes so will post if I find anything else interesting out through that research.

    LakeBaggerdpm50
  • miklcctmiklcct London, United KingdomMem​ber
    edited June 2020

    @suziedods said:
    It's the sauna.... while we in SF adore our sauna , after 35 some years of OWS, I am finding anecdotal ( ie personal) evidence that that lovely sauna is what #1- leads people to think they can stay in longer than they would normally because* there's a sauna I'll warm up there" and #2- that rewarming too quickly kicks them into fainting or in your case atriall fib.
    I am no expert, nor am I a doctor but I bet if you had just shivered you'd be fine.
    Again, anecdotal.. I know there is research out there on the cold and the heart but not so much on the rewarming process and the heart.

    I fell into the mistake of "there's a sauna I'll warm up there" last year although I didn't stay in longer than before (I was limiting myself to at most half an hour in such temperature). God why couldn't I find a travel website which warns against going into the sauna after swimming when I was looking up sauna etiquette?! It made my sauna trip went wrong last year!

    People called the police and sent me to the hospital. When I was removed from the sauna my body temperature was 35.1°C. There was no complication.

    @David said:
    Hi Phil

    Sorry to read about your problem with Atrial Fibrillation. Its fascinating to read your account but I guess not so much fun to experience. I am glad you seem to have good health care and the doctors have helped you.
    The Temperature of 6.8 deg C is quite cold! I say quite with a smile on my face because I am currently struggling to maintain my training because the pool and sea temperatures are hovering at 28 deg C. I was wishing for colder water yesterday and after an hour of fast sets I was dehydrated! I had to drink two liters of water before I started to feel normal again. I dream of swimming in 12 to 18 deg C water :)

    I'm now in the same position as you now @David . the pool and sea temperatures where I live are now 28°C so I can no longer maintain winter-level training, and considering to stop completely when the temperature continue to rise over the summer. I dream of swimming in 15 - 20°C water which is only possible 3 months per year (January to March).

  • ColmBreathnachColmBreathnach Charter Member

    @mrjamiehinton said:
    I came across this thread researching my own AFib and wanted to add my experience in case it helps others. From my own case, I believe there is something very specific about swimming in cool/cold water that can trigger AFib if you have a predisposition for it (either a dilated atrium, low heart rate, extra conductive tissue etc.).

    Hi Jamie,
    I wonder could it be postural? Swimming is horizontal, running is vertical.
    Perhaps also it's temperature related, did it happen to you in a warm pool or colder open water?
    Interesting post. Thank you for the insight.

    Copelj26
  • mrjamiehintonmrjamiehinton UKNew Member

    @ColmBreathnach said:

    @mrjamiehinton said:
    I came across this thread researching my own AFib and wanted to add my experience in case it helps others. From my own case, I believe there is something very specific about swimming in cool/cold water that can trigger AFib if you have a predisposition for it (either a dilated atrium, low heart rate, extra conductive tissue etc.).

    Hi Jamie,
    I wonder could it be postural? Swimming is horizontal, running is vertical.
    Perhaps also it's temperature related, did it happen to you in a warm pool or colder open water?
    Interesting post. Thank you for the insight.

    Thanks Colm,

    Yes I think there could also be something in the posture. I've read a few things mentioning that a 'supine' position can increase AFib occurance (presumably more related to 'lying down' but still may logically extend to any horizontal position).

    Yes temperature I'm sure is also a factor. It did come on in a pool originally + a few months back, but seemed to come on a lot quicker when I was in cold water last weekend.

    The other factor I'm certain plays a part is hydration. I can't be sure about the 2 times in the middle, but the initial episode in 2017 and the one last weekend I was very hydrated. Hydration levels reliably affect my resting heart rate... the more hydrated I am the lower it drops, the harder it beats, and the more variable time there is between beats. I think this variability along with the length of time between beats seems to make it more likely to 'trip'.

    Part of me wants to experiment... but I'm also very aware that 'AFib begets AFib' so probably prudent to avoid!

  • I've been reading this thread with interest - I was diagnosed with PVCs about 10 years ago. I'll have stretches of time where I don't feel anything at all, and stretches where it's really uncomfortable, unnerving, and unrelenting. I have noticed that two triggers are cold water (depending on the day, anything below 70F can do it) and holding my breath for too long.
    @Salty_Phil do you mind if I ask how the doctors diagnosed your condition (which tests, etc.)?

    JSwim
  • ColmBreathnachColmBreathnach Charter Member

    Part of me wants to experiment...

    No commitment. That's what's wrong with ye youngsters today.....

    mrjamiehintonIronMike
  • devartsdevarts North CarolinaNew Member
    edited May 2021

    Thanks for your very interesting and helpful posts about arrhythmias and cold water swimming.

    I’ve been a year ‘round pool swimmer for decades (US Masters Swimming member), late 60’s, in the US (North Carolina). I’ve occasionally enjoyed lake and ocean swimming in various locales and temp’s around NC and the world. Constrained some by the pandemic, recently I joined friends for an open water swim at a local lake with early May temps around 21-23 C. We swam for about an hour and I noticed arrhythmias (my friends were wearing wetsuits; I was not). These were similar to arrhythmias that I had experienced at various times during my life, not usually related to strenuous exercise. These turned out to be a relatively common and benign paroxysmal atrial tachycardia (PAT). All tests of my heart over the years, including stress, turned up nothing abnormal or unhealthy.

    This morning, after it occurred again during this lake swim, I decided to look up why. I came upon this UK study published in 2012

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459038/

    that may explain why very healthy swimmers and cold water “dippers” of all ages experience arrhythmias, including fatal ones that are categorized as “drowning”. Their research shows an apparent “conflict” between the body’s normal (autonomic system) response to being plunged into colder water, one that slows the heart and the other that speeds it up. This can lead to the arrhythmias that I experienced during and after my swim.

    - Dale in Durham

    Solomrjamiehinton
  • mrjamiehintonmrjamiehinton UKNew Member
    edited June 2021

    What a fascinating article, thanks for sharing @devarts . That combination of the "diving response" slowing the heart and "breath hold/release response" speeding it up actually very well describes the way I've always instinctively felt my body reacted when swimming. Particularly during a race or intervals often my heart rate would go super low as I pushed off the wall, then speed up as I took my first breath, and ultimately change rate on the fly depending on my breathing pattern. When this variability was at it's most obvious I always knew I was 'in shape'. This idea of those two systems firing simultaneously (or closely together) seems a very plausible description for why swimming (particularly cold water) triggers my Afib.

  • RandalRandal Sydney, AustraliaNew Member

    Hi All, I note this thread has been going sometime but wanted to contribute. I’m a regular ocean swimmer in Sydney, Aus. Over a yr ago I had a blackout during swimming and subsequently 3 more. Pretty scary because it was a real blackout … not just dizziness. Fortunately I was swimming with friends. PS. I am in my 50’s … however am v.active & do a variety of sports. After a yr of tests for cardio, neuro, ENT, everything, I was finally diagnosed with heartblock (bifascicular block). Simply put, there’s a problem with the ‘electrics’, I.e. conduction from the node to the ventricles. I now have a pacemaker and just started getting back in the ocean😁. So far, so good! But issue that was never answered was why the blackouts only happened during swimming? With help from Dr Google I have found some fascinating research suggesting that cold water submersion (especially face in water) + holding your breath can be a trigger for cardiac arrhythmias. In fact one article suggests that this ‘may be responsible for deaths that have previously wrongly been ascribed to drowning or hypothermia.’ (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459038/)
    Btw, ‘cold water’ means anything under 23C … perhaps not cold by your stds! I am still researching because it’s not definitive & hard to find precise answers. Interested to know if anyone else had similar experiences.

    LakeBaggerSwimmersuz
  • LakeBaggerLakeBagger Central OregonSenior Member

    Thanks for your post @Randal and glad you’re ok! I came across that article awhile ago and the (dramatic) title got stuck in my head and shows up frequently when I get in cold water :)

    As a result of this exact concern, I do head up breastroke until I stop gasping, then backstroke, and then when the cold shock has worn off, I put my face in. This way, I’m doing the sympathetic response first before I do the parasympathetic part, hopefully avoiding the “autonomic conflict” they’re talking about.

    I realize this is not an easy option for swimmers who need to dive under surf to begin their swims, but still something to be aware of at least until a swimmer’s cold shock response has been habituated.

    Swimmersuz
  • curlycurly Issaquah, WASenior Member

    This was an interesting read for me and I'd like to present a different view on this issue. I'm going to get a little more open than I usually do in any forum and reveal a little health info here. So bear with me because I'm pretty private.

    I have a condition that is called vasolvagal syncope. I'm not sure if it's a condition or a result, so excuse my lack of medical accuracy here. But the issue is that when a particular stimulus or trigger hits, your brain signals your body incorrectly and your heart rate and blood pressure drop dramatically. In my case there are a couple triggers that I'm aware of, and avoid. I got tested for all sorts of heart conditions after a particularly scary incident, and that's when I found out about vasovagal syncope.

    One aspect of all this is that when I'm really cold and warm up too quickly, I'll get pretty faint. When I was younger I actually keeled over during a cold to warm transition. I've read a lot about syncope and vasodilation and I think that the physical reactions combine to knock me out. When you consider that I have a low heart rate and low blood pressure due to my physical fitness, it's a bit ironic that those are the very things that can knock me unconscious. As you might imagine, this gives my kayaker nightmares.

    So while fibrillation could definitely be an issue in cold water immersion, one should also look at the warming back up phase very carefully. BTW, when I was tested, I went unconscious and my heart stopped for 30 seconds. They were standing by with paddles when I came to. I was later told that the paddles wouldn't have done anything, because the issue was that my blood pressure went so low, the heart wouldn't have been able to pump anything. It's like a pump that isn't primed apparently.

    And that's how I avoided having a pacemaker implanted. So there's some food for thought y'all.

    LakeBaggerSwimmersuz
  • LakeBaggerLakeBagger Central OregonSenior Member

    Thanks for sharing this story, @curly. It's pretty important for people to understand experiences like yours, IMHO.

    I think these are two distinct dangers associated with cold swimming/blood pressure/heart functioning. It seems to me, the autonomic conflict is a risk when getting into the water, whereas sudden changes in blood pressure due to quickly lessening vasoconstriction would be a danger after exiting to water (even for swimmers without vasovagal syncope).

    Here is a paper Tipton sent me when I was nerding out on this stuff a few years back. I had asked him why the research subjects in his studies were rewarmed in hot baths, since we are always advised in our community to not do that. He said that for semi-conscious, profoundly cold people, passive rewarming is best, but for superficial coldness, a hot bath is fine. He said showers should be avoided (or done only with a chair), due to the possibility of "rewarming collapse" and linked the following paper.

    https://www.researchgate.net/profile/Mike-Tipton/publication/21341061_Circum-Rescue_Collapse_Collapse_sometimes_fatal_associated_with_rescue_of_immersion_victims/links/0deec530b649d38fb8000000/Circum-Rescue-Collapse-Collapse-sometimes-fatal-associated-with-rescue-of-immersion-victims.pdf

  • curlycurly Issaquah, WASenior Member

    @LakeBagger I finally got around to reading the article. It used a number of medical terms and multi-syllable words that were a little beyond my pay grade. However, the overall gist of the study was really parallel to some of my experiences.

    One of the key moments in the study was when they were talking about vertical vs horizontal positioning of the subject. This was very much addressing the issue of low blood pressure in the arteries. They even observed the issue of blood pooling in the legs. This is really significant!

    One of the things I learned about vasovagal syncope is that the arteries and veins in your legs actually help to pump blood back to the heart. With the reduced pressure and systemic confusion, the blood doesn't get pumped back and flows get slowed or stopped. Heart doesn't get blood and all goes haywire.

    So one of my critical defenses against an incoming collapse is to get horizontal and raise my legs. Either support by a chair, wall or whatever will lift my legs higher than my heart. I also tense and release my leg muscles as much as I can at that moment. It is absolutely 100% effective. With that in mind, someone experiencing after drop, or even just feeling a little wonky after a cold swim, should get horizontal and get those legs up. My guess is that it would be a very effective defense.

    One other hypothetical musing on all this. It's possible that we long distance swimmers who use a very soft and slow kick are exacerbating the problem. The legs are just along for the ride and are doing the bare minimum. Therefore we aren't really doing anything to call for more blood flow at that end. I don't know if there's any merit to that thought, but it's interesting to note.

    I'm sorry that I can't write it in more medically authoritative terms, but maybe someone else can translate this into useful information. This is anecdotal experience, so take it for what it's worth.

    LakeBaggerSwimmersuz
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