Swallow syncope

Hi everyone. I have not yet had a PM fitted but I had an implanted loop recorder inserted 2 years ago and my Cardiologist has recommended a PM although not urgently.

I am a 62 year old triathlon coach who has exercised all my life. My resting HR is 32 due to an enlarged heart brought on by endurance sports and it has never caused me any issues until 7 years ago when I fainted unexpectedly. Long story short, it appears that I have a condition called 'Swallow syncope' and specifically, my HR plummets if I swallow very cold drinks, (usually carbonated for some reason). This isn't really problematic as I don't drink fizzy drinks except the odd lager/cider, but about three months ago, I almost fainted when I swallowed some toast. A PM would completely solve the issue, but my Cardiologist has said that the lowest I could be paced at is 50bpm, which seems odd. This would mean that when I'm at rest, the PM would be powering me continuously. I posed the same question on a Facebook forum and somebody has a device that goes as low as 40, which I would be happier with.

Does anybody have a similar condition and if so, would they reccomend the PM solution? Also, does anybody have a PM that has been adjusted lower than 50 please, that is available on the NHS?

Thanks for your help.



by Gemita - 2020-01-02 11:23:03

Hello Gra Kay,

Unusual to find someone who suffers from this.  I have suffered from swallow syncope since childhood (and it doesn't always matter what I swallow, sometimes the action of swallowing in itself or even sips of tepid water can set it off).  I have had all sorts of neurological investigations.  Swallow syncope has landed me in hospital many a time, particularly now that I have also developed arrhythmias which I firmly believe have in part been triggered by my swallowing difficulties.  We must remember the close proximity of our oesophagus to our heart, so no wonder problems in the oesophagus with swallowing can trigger all sorts of unwanted heart rhythms.

I now have a dual chamber pacemaker set at a steady rate of 70 bpm night and day and for me my symptoms have vastly improved (both with swallowing and with my arrhythmias).   I find that blood flow to all my organs is now better whereas before I was always icy cold. Swallowing difficulties would be at their worst during these "icy" symptoms.  Like you I have a naturally low heart rate (during normal sinus rhythm but not during my arrhythmias when tachycardia is a real problem).  I also have very low BP and quite honestly although my doctors felt it was a healthy sign at first, when they implanted long term monitoring  (ILR Reveal Link) - which confirmed increasing arrhythmias, pausing, syncope, they decided a pacemaker was the way to go.  It may not work for everyone, but it certainly works for me.

You can work with your electrophysiologist and/or Cardiologist to find your optimum settings which are right for you.  Talk to him/her about your thoughts - they like patients to be proactive.  I am an NHS patient of a main London, UK hospital.  Good luck


Minimum pacing rates and modern PMs

by crustyg - 2020-01-02 12:21:08

Hi: I too have an enlarged heart from endurance sports and ended up with SSS+brady and chronotropic incompetence (can't raise my HR beyond 115bpm by myself).  AV conduction fine, resting HR about 38, but running on a junctional rhythm for several years as my SA node has failed completely so no A->V synchrony, and very large atria.

I had my box adjusted from 50/160 to 45/160 this summer (so you *can* be paced at 45bpm, asssuming you have the 'right' PM fitted (more about this below).  I was back in the hosp next morning pleading for them to put it back to 50bpm!  Discovered during that morning's Pilates class that my cardiac output at 45bpm was just too low for any real exercise from supine.  As I live a short cycle ride from the teaching hospital where I trained, this wasn't too difficult.

So!  You need a PM that supports what *you* need, not what your EP doc (or worse, the EP techs) are familiar or comfortable with.  My EP was nearly swearing when fitting my leads (generally it's wise for later MRI studies, if needed) to have leads and PM from the same supplier, and he doesn't normally use that vendor's leads and the shapes are different between vendors.  As long as your 'local' PM clinic has a machine to interrogate the chosen box then you can have any of the big three PM vendors.  You need to know if you have chrono-incompetence or any degree of SA disease, as this box is going to be in you for at least 7years.  *IF* you have these, then as a cylist your only real choice is BostonScientific as only they (of the big 3) have the ability to drive the rate response algorithm sensibly for a road cyclist (little upper body movement, which is all that every other vendor can offer, driven by an accelerometer).  My local teaching hospital is a big user of BostonSci PMs paid for by the NHS, as well as the little Latitude remote monitor which sits under my bed to let them know if I drop into AF.

PM capabilities have changed over the years - some long time ago hardly any boxes for adults could pace >180bpm, and even now most interrogation/programmer boxes will moan if asked to set lower-rate-limit <50bpm.  But PMs are available which can do what you *need*, and not merely what your EP is familiar/comfortable with.  Ask him/her how many serious athletes he has in his patient roster.  Unless your EP doc has a pro-cyling team or athletics club then it's almost certainly going to be <5.  Which is not a lot of experience.

I'm sorry to have to say that the choice of PM is often affected by money: deals with the PM vendors for a free interrogation machine (worth £ks) if they implant enough PMs pa from that vendor (usually at a hospital or department level).  Just like free freezers to stock ice-cream from <vendor a> etc.  For a few docs, it's a lot closer to the ethical wind than that...  But this needs to be something that you go into with your eyes wide open: it'll be the devil to change once fitted.

Would we recommend a PM?  Gemita has given a comprehensive answer from the expert personal perspective.  You may well end up losing your driving licence if you decline a PM - if you almost fainted.  GP friend of mine had a first epileptic fit in early 50s out of the blue => no driving for a year.  The DVLA doesn't *do* discretion - it's a bureaucratic machine.  Does it matter that you will be paced all of the time - no, not at all.  Your BP *might* increase a little, but that's easily checked with home BP monitoring.  You'll be committed to annual PM checks and will have to face a PM box change every so many years (you might be able to charm your EP doc into giving you the large battery box - EL - which could easily last 14+years).  There *are* risks in having leads implanted into your heart, but they are small compared to other risks that we happily accept (road cycling at night, for example).

You won't be allowed to drive for a week after implantation, you won't be able to swim for about six weeks after implantation, but after that you're fine for almost any and every sport - although serious contact sports (rugby), mixed-martial arts, and taking up welding for work or fun is probably off the table too! 

Mine has been a great success and I can keep up with my chums cycling up into the mountains, and running, swimming and core-muscle classes are all ok.  Going from 38 kicks in the chest at night (no A->V sync) to 50 smooth heart beats was no problem for sleeping.  32->45bpm or 40 should be no problem for you.  You will get several oppportunities to have your PM 'tuned' for you - it's not just a set-once-and-leave-for-a-year job.  You can even have it tuned specifically for your requirements, but that will require more charm and/or money.

Swallow syncope

by Gra Kay - 2020-01-02 13:02:55

Thanks very much both of you. This might sound ridiculous, but I was under the impression that if I had a PM bolted onto my heart, it would just kick in if I dropped below a given BPM? What's the upper setting for? My heart has a normal range of between 32 and 142. I hit 142 coming across a finish line after a 800m race, but I would normally be in zone 5 between about 134 - 139. I don't think I need any extra assistance other than the bottom end?



by Gemita - 2020-01-02 14:16:22

Hello Gra Kay,

I will leave Crustyg to fill in all the gaps because he is very good at that and I am relatively new to pacing and I don't have his technical knowledge and expertise. 

My understanding is that yes the pacemaker kicks in when my heart rate falls beneath my set rate of 70 bpm (the minimum rate set by my pacemaker clinic).  I am almost 98% paced (right atrium) since my own heart rate is no where near 70 bpm. As for the upper heart rate, I see it as a "cap" (the maximum heart rate set by the pacemaker clinic).  When we start exercising, you might be surprised how quickly our heart rates may go up to your values (134-139 bpm) and you don't want to be restricted in any way just as you are getting into your stride.  If they set an upper rate cap of say 150 bpm you might get to that pretty easily and then start to feel "breathless" or in some way "held back" from fully performing.  

For me personally, my understanding is that the upper limit is just a "warning cap" so that if my heart rate were (for example during arrhythmias) to exceed my upper set rate of 175 bpm, my pacemaker would kick in and protect me by switching pacemaker modes (i.e. switching from pacing in the right atrium to pacing in the right ventricle) so that it doesn't track my atrial arrhythmia(s) - which can soar to extremely high speeds causing instability.  My pacemaker cannot slow down my atrial tachyarrhythmias, but it can help to stabilise me by switching modes.  Yes it is all very complicated 

Swallow syncope

by Gra Kay - 2020-01-02 15:52:50

Thanks Gemita. I think my issue is just the swallow syncope rather than a heart issue per se. I'll book another appointment with the Cardiologist I think before I make a final decision.


another rare bird

by Pacemaker_Sally - 2020-01-03 00:07:36

Hi Gra - I also have swallow syncope and a perfectly healthy heart. When I swallowed liquids, vitamin pills, or bread, I had a total AV block for up to 5 seconds. Not quite enough to cause a complate blackout, but I had a few close calls.

I have had a dual-chamber 'on demand' pacemaker since late October. I still know when I'm having a bad swallow, but the pacemaker kicks in seamlessly. I've had one adjustment since the initial impant. I have no idea what the settings are, but I seem to able to meditate and drop my HR down pretty low without feeling paced.

With surgery and now winter, I haven't been back on my bicycle yet, but I have had no issues with a brisk, mostly uphill, 4km walk to work. Sleeping seems ok too. You might be surprised how much more energy you have with a PM. 

All the best and keep us posted!

Max heart rate

by AgentX86 - 2020-01-03 00:33:16

The maximum heart rate keeps your heart from going into "pacemaker induced tachycardia".  This happens when the dual lead pacemaker fires in the ventrical before the AV node does and creates a "retrograde" signal in the AV node, which is then passed backwards to the atrium, which then is sensed by the pacemaker which fires the pacemaker again.  Rinse/repeat. Instant tachycardia.  This can be deadly, so the answer is to limit the ventricular rate so that the PM can't pace the ventricles at an unsafe rate.

Swallow syncope

by Gra Kay - 2020-01-03 04:38:27

Thanks Sally and Agent X. Both useful comments.

Upper rate probably not important to you

by crustyg - 2020-01-03 09:45:57

Thanks for the kind words Gemita: yes, any PM will have some sort of max rate setting (sometimes more than one), most of which *you* can ignore.  Your PM will be set to record 'events' if the detected HR goes well above your expected normal maxHR, so that your EP team can watch for developing arrhythmias.  Folk with SSS+chrono incompetence care a lot about this stuff, but you probably don't need to worry about maxHR!

For you, all that really matters at the moment is preventing your HR dropping too low => low BP => fainting.

Swallow syncope

by Gra Kay - 2020-01-03 10:09:00

Thanks again Crustyg, that's kind of what I had figured. I'm still keen to learn if people have devices that allow them to be set lower than 40 though?

Not documented - in the publically available docs

by crustyg - 2020-01-03 12:37:51

It's a good point: sadly the PM vendors don't seem to document max or min pacing rates that each box can deliver - at least not in the reference docs that I can obtain.

I am prepared to be surprised if someone can show me a vendor's PM capable of being set to <40bpm.  It starts to contradict the notion of a pace-maker any lower than this!  But the honest truth is, I don't know. MrTech might.  It's not so long ago that you'd struggle to get an EP doc to set lower rate <60bpm!

From your perspective, it's really unlikely that you will notice (for very long) a change of HR from 32 to 40bpm.  As I mentioned, I went from 38 to 50 and barely noticed it - but I always notice when they drive my HR up during a testing/interrogation session - big heart, I can always feel it if I pay attention.  And I sleep on my left side which makes each heartbeat even more noticeable - but I soon got used to the higher rate.

Swallow syncope

by Gra Kay - 2020-01-03 12:51:04

When I first had issues, my Cardiologist said it would be possible to have a bespoke setting to cater for my low normal HR but then he emigrated and the new bloke says not. I’m amazed as it can’t be overly difficult. If they can program it at 50, they can program it at 49 etc etc. I’ve managed 62 years with a Diesel engine for a heart, and I appreciate everybody saying I won’t notice the difference, but the thought of being powered by machine for a vast proportion of the day and night strikes me as bizarre, when an adjustment would save battery and still cure the issue. Thanks again for your input. 


by Gemita - 2020-01-03 12:52:37

Hello Gra Kay,

I would respectfully suggest that if you decided to have any future pacemaker set lower than 40 bpm minimum, it would defeat, in my opinion, the purpose of having a pacemaker implanted and you would probably not be protected from syncope in the future.  In this case, you might as well live without a pacemaker for the moment and cope with the occasional faint ?   Not sure that my pacemaker team would have agreed to give me a pacemaker on the basis of setting a less than 40 bpm minimum heart rate but if that is what you really want, then what can I say ?


by IAN MC - 2020-01-03 15:37:49

It is not unknown for athletes to have very low resting heart-rates.

I remember reading that Gordon Pirie's was 35 bpm . Having the lower limit set at your normal pre-pacemaker rate would seem to make sense to me .

I know the definition  of bradycardia is less than 60 bpm but we are not all  robots, some people break the rules.


Swallow syncope

by Gra Kay - 2020-01-03 15:58:55

Thanks Ian. I might be old, but I am a GB age group triathlete and also ran in the GB police team when I was younger. When my GP discovered my resting HR was so low back in the 1980’s it was investigated thoroughly and the upshot was that I had no abnormalities and they reassured me that I was fine. It was only in the last 7 years that the swallow syncope has manifested itself. If I miss 2 beats, I get a 6 second pause that makes my BP plummet. If I was paced at 32, once I missed the first beat the PM would kick in to prevent the 2nd missed beat. That’s my theory anyway!! Thanks for your input. 

Swallow syncope

by Gemita - 2020-01-03 17:09:08

Apologies if my message offended in any way. Yes we are all individual with our own unique health problems and treatment will be so different for each one of us. 

I wonder whether a “trial of temporary pacing” might be available or possible for you Gra Kay to see whether a pacemaker would help with your swallow syncope before you are totally committed.  You could then make lots of setting changes to see how your ideas would work in practise?  


Swallow syncope

by Gra Kay - 2020-01-03 17:11:55

I’m very difficult to offend Gemita! I’ve never heard of a trial?

This isn't a technical issue, it's a human one

by crustyg - 2020-01-04 03:17:42

Hi Gra Kay.  I think you're looking at this from the wrong perspective.  Most of the thread so far has been 'can I get a PM programmed to provide safety-net pacing at my usual HR of 32bpm?'

Whether you can or not probably isn't relevant. If you are to carry on driving you need to be certain that you avoid fainting, and you're going to have to find an EP doc who will sign papers to this effect - and this is the issue.

In the 2000ms or so between each of your LV contractions, the blood flow to your brain is coming from the blood stored in your aorta and the pressure is provided by the elasticity of your aorta walls.  But as we get older that elasticity reduces - hence the widening gap between systolic and diastolic pressures, so you get closer and closer to the critical level of brain blood flow before the next heart beat.  Your EP doc knows this and won't support you having a PM set to 32bpm, because although it might be enough for you now, as each year goes by that aorta is getting harder - and why would (s)he risk their reputation on a one-way bet against them?  Do you think they want to read about you in the Press as the 'old fool in W******* car-park who drives into other customers?'

I truly understand that a large part of your self-identity is bound up in your athletic life and history.  When I used to boast to my running mates about my low resting HR (about 44bpm) - and boasting is what it was - I genuinely thought that it showed how athletic I was, and I'm nowhere near the top-flight league that you inhabit.  You are going to have to let go some of that self-image, and accept that for your own safety - and others around you - your heart needs to beat faster.  Exactly how much faster is a challenge for you to negotiate with your EP doc.  45bpm is possible and realistic, much lower may be difficult for any EP doc to sign off.

The process of letting go is part of the emotional journey of becoming paced - and there are a *LOT* of us here who have been through that.  As Tracey_E has pointed out, recovery from the emotional injury can take a lot longer than the physical injury.

Pardon me for being so blunt.  And please do keep visiting and posting as your journey progresses.

Swallow syncope

by Gra Kay - 2020-01-04 04:51:30

Thanks Crustyg, I have already written to the Cardiologist requesting another appointment, so I'll see what he says and I'll let people know. Thanks for your support.

Autonomic Testing

by Gemita - 2020-01-04 04:54:38

When I had autonomic testing for swallow syncope at the National Neurological Hospital, London, there was a lady on the ward who was offered temporary pacing because doctors were doubtful her swallow syncope would be prevented by pacing.   She was a particularly difficult case I recall because she was ultimately found to have predominantly vasovagal syncope during swallowing.  When I met her some months afterwards during followup she told me that while her temporary pacing proved helpful in supporting heart rate, it did not help the vasovagal attacks which caused sudden, rapid falls in her blood pressure during swallowing, leading to syncope.   She was ultimately discharged on pharmacological treatment alone, so temporary pacing was a valuable diagnostic tool for her and her doctors.  

Have you had autonomic testing? If not, it may be a better way forward and give your doctors lots of additional info before you commit to a treatment that may not be completely effective.  There are so many potential causes for swallow syncope as you probably know and a full work up to rule out other possible causes/treatment may be helpful.

I dont know a great deal about temporary pacing. It still sounds quite invasive but I would certainly press for further testing/answers because you seem genuinely uncertain about the best way forward .  




Swallow syncope

by Gra Kay - 2020-01-04 05:17:45

Thanks Gemita. My problem is that the swallow syncope has occured about 4 times over 7 years and I only fainted once, 7 years ago, following a ridiculously early swim training session in Lanzarote and I gulped ice cold orange juice. Other than that, I feel perfectly well.

Watchful waiting ?

by Gemita - 2020-01-04 05:43:46

If that is the case, I would be inclined to leave well alone and take preventative measures to avoid triggering your symptoms.   Only my opinion.  Please let us know how you get on

Swallow syncope

by Gra Kay - 2020-01-07 18:04:56

What is a sensitised ANS please?

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