Vagal Atrial Fibrillation

I've been struggling with some night time symptoms for a few months now and I really can't work out what's going on. 

They only come on at rest and normally in bed at night or when watching TV and lying on the sofa. They may be positional as they sometimes go away if I move my sleeping position. They're worst when lying on my back and feel like a shaky feeling in my chest. It's a distinct cardiac sensation and can go on for quite some time.  The sensations - bizarrely - can also affect the nerves in my thighs. Weird I know! 

I know I shouldn't but I found an article on vagal AF and it sort of makes sense to me. Does it make any sense to anyone else who might know more about this condition? 

I've tried a Kardia mobile app and don't get anything but normal sinus rhythm.  At the end of my tether with it. 


weird sensation

by new to pace.... - 2023-02-04 18:31:48

sorry to hear you are going through these.  I am guessing the thigh nerves are from laying on your spine. Which are getting pinched,  as you say if you move these go away.  Makes sense not to lay on your back.

Cannot answer your other questions.

new to pace


by Penguin - 2023-02-04 18:52:22

Yes, it does make sense not to lie on my back if this triggers the sensation I agree, but I don't think it's pinched nerves in my spine. I've had a pinched nerve and the pain is sharp and sudden - makes you jump. It's not like that. It;s like a vibrating sensation / pulsing / electrical.   When it starts it's continuous and it;s wearing me out.  I'm pretty certain that it's an arrhythmia or something pacing related.  My ANS is pretty sensitive.

It came on after changes made to my settings and it won't go away. I've read that AF during sleep can be positional. It's definitely triggered when I lay on my left side and my back.

Thanks for the suggestion. Hope you're doing OK NTP ?


Yes I know vagal AF well

by Gemita - 2023-02-04 19:08:18

Penguin, it all makes perfect sense to me as a vagal AF sufferer, which can be defined as AF occurring mainly at rest, as heart rates naturally start to fall, although with my pacemaker set at 70 bpm this doesn’t happen often now unless I develop atrial premature beats which allow pausing, slowing of heart rate and then AF to start.  And yes, my AF and many other arrhythmias can be triggered or stopped by positional changes, from lying down to standing, changing sleep positions from right side to left side, then back to right side.

I usually feel my arrhythmias in my stomach and this is commonly reported and yes with a fibrillating arrhythmia like AF, the vibrations can be felt in other areas too.  I get that “sinking feeling” - that feeling of doom - as they start. 

Try to get long term external Holter or Zio Patch monitoring to pick up these disturbances, or take your Kardia Mobile print outs to your clinic for assessment/diagnosis.  Keep the pressure up until they confirm the arrhythmia present or a pacing problem.  When I first got diagnosed with AFib, this is what I found out:-

To the list of the causes or triggers of A-Fib such as heart disease, thyroid problems, fibrosis, etc., we should also add the malfunctioning of the Sympathetic and the Parasympathetic Nervous Systems. The Sympathetic Nervous System reacts to stress, stimulants, etc. causing the heart to speed up and the blood vessels to constrict. A-Fib arising from an overactive Sympathetic Nervous System is called Adrenergic A-Fib. The Vagus Nerve, in contrast, controls the abdomen and is part of the Parasympathetic Nervous System which slows the heart and dilates the blood vessels. A-Fib arising from an overactive Parasympathetic Nervous System is called Vagal (Vagotonic) A-Fib.

Adrenergic and Vagotonic forms of paroxysmal A-Fib are uncommon. However, if your A-Fib is normally triggered by exercise, stress, stimulants, exertion, etc., then you may have "Adrenergically-Mediated" A-Fib. People with structural heart disease seem more prone to Adrenergic A-Fib. But if your A-Fib occurs at night, after a meal, when resting after exercising, or when you have digestive problems, then you may have "Vagally-Mediated" A-Fib. Many people have a mix of both Adrenergic and Vagal A-Fib.  Perhaps A-Fib begins as a nervous system problem, then becomes a heart problem after the arrhythmia is established.

It's important to determine if you have one or the other so that you can better identify what triggers your A-Fib, and because the treatments are often different for each. For example, beta-blockers usually don't work well with Vagal A-Fib (a Calcium Channel Blocker like Diltiazem might work better) though it's difficult to generalize about A-Fib treatments, because each person reacts so individually.  Current research hasn't indicated yet whether Pulmonary Vein Ablation is more or less effective or appropriate for Adrenergic than for Vagal A-Fib. However, it seems that both Adrenergic and Vagal A-Fib are focal in origin (come from specific points or spots in the heart), and can presumably be treated with a Pulmonary Vein Ablation (Isolation) procedure.

Of course having said all of the above, it is highly possible that your sensations, vibrations, quivering or whatever else you feel could be coming from a pacing/lead problem and I appreciate you are looking into this possibility also.  I don't think you are on any meds?


by Lavender - 2023-02-04 19:58:42

I have a vibration sensation when drowsy that used to be even stronger until they changed the pacemaker ring to can setting. I still have it very mildly most mornings as I'm awakening. 

I did see this article on vagal afib and wondered if you would be interested in the many comments made by others regarding this. The comments are at the bottom of the article.


by Julros - 2023-02-04 20:41:45

As I read your discription, it sounds sort of like the phrenic nerve stimulation I had from my LV lead. I don't believe you have one, but I still wonder about you having these sensations after reprograming. My symptoms were positional, and I would feel pulsations in my abdomen, and the surface of my belly would visibly twitch. They were able to adjust the settings to fix this. 

similar situation happened to me

by Nina38 - 2023-02-04 23:57:02

When I was diagnosed with Lyme disease, I felt weird vibrating sensations and AF but I think it was my vagus nerve.. once I got the treatment and learned healthy ways to improve my vagus nerve... it all went away. 

Really Helpful Comments

by Penguin - 2023-02-05 05:19:17

Thank you for those suggestions and comments. They're all sensible and worth thinking about. 

Gemita, as always thank you for your descriptive and full answer. No meds currently as BP has never been high and most cardiac meds lower BP.  AT has never been symptomatic enough to treat. Current symptoms must be around 60 bpm - my base rate. I've caught a few runs around 70 bpm without obvious trigger or cause. 

Bizzarely I have started getting (mild) heartburn (which I never get) and wonder if this is anything to do with it. I've also been very stressed for about 3 years now - with no let up. None of that's good for the ANS I know. 

I had a particularly bad night last night - 1 small glass of red wine with dinner - definite trigger. Feeling vaguely dizzy this morning and exhausted. 

Nina, thank you. No lyme disease - certain of that - but thank you re your confirmation of the weird vibrating sensations linked to vagus nerves. Sounds v.similar and plausible.  I think I'm going to have to somehow get my stress levels under control. 

Julros, I have a dual lead device and one lead is sub-optimal (v.lead) but is sensing well enough I'm told. I get noise readings.  I'd struggle to identify a lead related issue as I've no experience of it.  Symptoms have come on since my last clinic appointment - very definite link to that, but whether or not it's a lead issue I have no idea. 

Lavender, yes again similar thing to you. It's often there in the morning mildly, then stops when I start moving around and sit up or get up. Thank you for the link - it's an interesting read - and the comments.  I read it with interest.  Low EF (30's) prior to pacing, and another dip quite a few years ago when VP was high - Q's about pumping action of my heart raised and resulting arrhythmia triggered.  EP satisfied with recent echo - all normal. 

Lavender, one other thing - I didn't understand your sentence that said, 'until they changed the pacemaker ring to can setting' ??  Could you explain what 'ring to can setting' is please? That's a new one on me! 

Overall, thank you very much to all who answered. You've given me a few things to consider that I hadn't thought about. 

Best Wishes

Gastric Reflux/gastric disturbances are a most definite trigger for rhythm disturbances

by Gemita - 2023-02-05 06:23:18

Penguin, I am not surprised you have heart burn with your continuing difficulties and yes reflux, an ulcer, a hiatal hernia and anything like this that affects digestion can be a strong trigger for an arrhythmia like AFib.  Just search the web and see for yourself.

You could trial a few weeks on a Proton Pump Inhibitor to see if it helps.  If it does, you might have your answer.  Have a read of the link below on gastric reflux as a trigger.  Unfortunately wine is a strong AF trigger for me and can be for many of us and may cause worsening reflux as well (as can caffeine and caffeine does this by relaxing the lower oesophageal sphincter, which can result in reflux of stomach acids).

Stress will be an even stronger trigger for all manner of health problems and any stress or upset can really trigger an AF attack for me.  It did the other day when I got upset.  Our hearts are so sensitive to stress and will quickly throw out rhythm disturbances.  But of course I am making assumptions that may not be the case for you and I hope you will find that elusive cause(s) for your symptoms very very soon dear Penguin.  Look also at all the causes for your current stress and try to address these where you can.  Without getting to the root cause you may not be able to identify the full extent of the problem.

Ring to the can

by Lavender - 2023-02-05 10:31:28

The pacemaker is "the can" (canister) as per my Boston Scientific tech. There are rings on the leads which transmit to the can. Mine was originally set as ring (electrode) three on the lead transmitting to the can. When I complained that I felt vibration while lying and at rest, but none while up and about, they tested me for what Julros mentioned: phrenic nerve stimulation. 

They tested each lead to see if they could replicate the vibration. They couldn't. HOWEVER I later realized that it happens only when lying down. They tested me while sitting up. I'm still not convinced this isn't part of the vibration issue. 

At that same visit, the tech suggested changing from ring three to the can to ring four to the can to ease the vibration sensation. The tech told me that 80- 90% of pacemaker people have this vibration and get used to it. I noticed much less vibration immediately that night but it's still present.  It no longer awakens me nightly though. 

My printout from that day says:

LV (Pace)       LVRing 4>>Can

LV (Sense)      LVTip>>LVRing2

For heartburn-no alcohol, caffeine, tomato products, or chocolate!


by Penguin - 2023-02-05 13:25:44

Well that's interesting information Lavender. I thought your 'ring / can' references were a typo! Pleased I asked now!  Thank you. It's certainly something to consider. 

Gemita, thank you for the further suggestions. I'll keep an eye on the heartburn, it's not a major issue just unusual for me.  Last time I had it I was pregnant and that's definitely not the case!!

Re: other triggers and stress. Seems most likely to me, but yes I need to get to the bottom of it. I've caught up with some sleep this afternoon and feel better for that, but got the symptoms as soon as I laid down and woke up with them. At least I was tired enough to sleep through them!  Small blessings x 



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