Arrhythmia Alliance
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Has anyone else who has had an SVT attack had mini-blackouts during? In the days leading up to my attack with palpitations for days, I was having this for seconds at a time, and during the attack in A & E, with heart going up as high as 300bpm for 4-5 hours, I'd be unable to speak for just a minute or so, and I heard the nurse call this 'instant seizures'. With one attack only, I am wondering if this is partly why I was fast-tracked for an ablation (which I have cancelled as I couldn't get to meet with the EP beforehand with my questions). Anyone know if these were TIAs? Thanks.

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@stargazer61 I messaged u


@stargazer61 I replied


This is a slightly weird story. It doesn't sound like you had a typical SVT - the rate would not suddenly jump to 300 bpm. Maybe it was atrial flutter. If it really did go that fast, having a blackout/siezure would not be surprising - it is not the same as a TIA (which id due to blood clots) but just a sign of dropping blood pressure, with no lasting damage done.

Relating to your previous posts I think it is important that you have a proper consultation with your EP doc and go over the ECG tracings from your hospital admission so you can have an explanation of what exactly happened, what caused it, how it was affected by the drugs you were given and what kind of ablation they are planning to do. It may be that the tracings are not clear (or lost) so the EP doc will have to start from scratch with an electrophysiology study to look for any abnormal pathway and then zap it - but this is not very satisfactory.

A reasonable strategy is to just see if you have any further attacks before deciding on an ablation - and this time don't wait for days before going to hospital. If an attack has just started it's much easier to stop it with adenosine and an ECG recorded when this is injected can be very informative about the type of SVT or other arrhythmia it is.


Thanks very much for your words and time. I so want to sit down with the EP, but all attempts to push for that are led to nothing, so i have to just wait. One of the first things i noticed whilst reading up on svt was that no one mentioned rates above 220. I remember the bpm when i went in was 170, then when they were telling me about adenosine it was 240, after in the ward the nurse said 270 and back at a and e the second time, the same doctor said that the first time my bpm had went to 300bpm. I have asked if i can see the notes but have had no reply as such. Waiting so long is driving me mad. If you saw my previous posts you will have seen i reduced my medication on my own, i have gradually come to half so am on 2.5mg bisoprolol and 2 x 50mg flecainide. (Not altered apixiban) But I am afraid to reduce further particularly because of these high rates if i have another attack. I can see the need for rate control, but if svt is regular, why do i need to be on flecainide? Is it because adenosine and betablockers didn't work and flecainide brought me back into nsr? Is it normal to take both, a rythm and rate controller both at the same time, or do some people take just one?

I am sorry, i am rambling on, but i'll leave on a lighter note -

I managed to stumble through this joke as they prepared to inject me with the adenosine - a man went into a pub and asked for a pint of adenosine triphosphate and the barman said 'that'll be 80p'...

Much gratitude to you, the low blood pressure makes sense, i was really scared it was mini-strokes and every fear explained is more stress relieved, the more easily i can breathe and therefore the better for my heart. Thanks!

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ATP - good one, I'll save this.

Yes it's fine to be on both flecainide and bisoprolol - atrial flutter and some kinds of SVT respond to flecainide so it's best to continue both until it has been sorted out. It's probably the bisoprolol, a beta blocker (meaning it blocks adrenaline), that is making you more fatigued but provided they didn't find anything else wrong with your heart you can push through the tiredness and keep active.

On the subject of seeing the EP doc, there may be a long waiting list on the NHS* but you could ask to see him/her privately and that would give more time for discussion as well. The NHS secretary should be able to give you a number to call.


Can't afford to do that, but your reply has reassured me, i'll continue with the meds. Good man!

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Hi Jonathan,

I have had PVCs since age 36, on and off, which I contributed to hormones.  After a recent dizzy spell accompanying pain in my left arm? I was diagnosed with SVT also.    Meds didnt work, so I am scheduled for an ablation.  Is there any connection between TIAs and SVT?  I literally could   not remember what I had done the previous day and it scared me.  I'm always misplacing things too.  Since I was discharged from the hospital i have occasional chest pain, direct and sharp, to the left of my sternum.  does not increase with exertion, I tried that.  I understand why a plumbing problem would cause chest pain, but why electrical?  for working so  hard?

thx  Megan


Hi Megan,

No, SVT does not cause TIAs but anything that makes you feel really ill can make you forget what happened in the hours beforehand (it interferes with the process of converting a temporary memory into a permanent one).

SVT can easily cause angina (tightness across the chest and ache in the left arm) because the heart only gets its own blood flow in the gaps between beats, and when the heart is going too fast the gaps disappear and so the heart doesn't get much blood for itself. So it's a matter of timing rather than plumbing but has the same effect.  Interestingly it doesn't happen so much with exercise because the adrenaline makes each beat shorter so there are still gaps.

But the sharp pains to the left of the sternum don't sound like heart pains at all – they are much more likely to be just due to a trapped nerve in your back (between your shoulder blades). They are helped by sitting up nice and straight.

As regards misplacing things that could just be due to worry, e.g. about your ablation, but if you're convinced it is getting progressively worse you could discuss with your GP about having a brain scan.

One other thing: it's a bit unusual to go for an ablation after just one attack of SVT because it could have been caused by a temporary problem (like a virus) and so they may not find anything wrong to ablate.

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Hi Stargazer61,

I used to black out and convulse with my SVT before my first ablation my heart rate only reached 210bpm with it. After my first ablation it stopped the black outs and then had a second ablation a year later, but then I collapsed again last November with the palpitations. So I know how you feel, but the EP/Cardiologists still aren't sure what's causing them. Not much help to you I know, but interested to see how you get on...

All the best x


Conquering worries and fears is easier said than done eh! I am trying so hard to be positive, failing miserably some days, but that's okay too! It's the hanging about with it all waiting to see the EP that's testing me most! If i hadn't pushed tho, i would still be unaware that i'd get a letter with an ablation date in march, so at least i know that and the gp and cardio can see why i want to talk to him, if only i didn't have to cancel and go to bottom of waiting list to see him in clinic i'd be content! I thought cancelling the ablation to talk to him first would mean i'd see him on that date in march, but no, it's a different waiting list, and there is no way to keep ablation and see him first. Aaaaaaagh!! All that 'should i do this...or that...' can drive you mental! I did that all night one night, didn't sleep one wink!!! To avoid that, i'm walking about with my fingers in mudras, chanting and all bloody sorts with a soothing heartbeat in the background trying to brainwash myself into calm!!! Breathe...breathe...breathe...

Hope you are feeling well Sophie, a few words really can help when you feel blue, so thanks and a hearthug to you x

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Easier said than done I know! You will be positive and you can push through this :) Just make sure you get the support you need and remember you come first, so don't let them muck you around with appointments!

Keep us updated with any news :)



My heart rate has reached 230 with SVT but the hospital normally seemed surprised that I was so awake and never let me walk Incase of a blackout. SVT is a broad umbrella name for lots of different cases as I understand so everyone can be slightly different. Mine apparently was a rare case as I had multiple paths which only was discovered during my first ablation. Good luck with everything try and stay positive xxx

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I had svt and when bad would not be able to move or speak, I'd flush and it would come over me like a wave over and over again. My heart rate maxed on ecg at 240. I did black out with this too but the blackouts came with no warning I'd just come round and realise what had happened. It's very scary as when I was paralysed with it I was aware of everything going on as hearing was not affected but I could not move or respond to anyone. They nearly shocked me at the hospital because of it till a nurse screamed she has a pulse!. Get checked properly and discuss options. I was put on meds but only to get me till my scheduled ablation day.


Can i please ask how many attacks you'd had pre-ablation and how long they lasted for? That sounds horrible, i looked normal i think, could hear and everything like you, just could not respond, scary stuff! Hope you are in a good space now? The nearest i can get to even a month when i might have first ep visit is ' you should hear something before the end of april' so i continue to go it alone, feel a bit left to my own devices, it's not a good feeling! Thanks for replying.


From 2009 to 2015 I had lots and they became more frequent. They would last for days sometimes just wave after wave of it. Blackouts not often but fear always there. Felt waves daily of varying degrees, but think now that they were the ectopics as its how I feel now.the big waves as I called them were terrifying and exhausting both mentally and pysically but because the docs had said it was panic attacks I never made a fuss and just pushed through! When I was diagnosed in May 2015 they put me on 10mg bisoprolol and 200 flecainide but ended up back in hospital prior to first ablation and then again after first ablation with vt. I'd say my big waves were around 39-40 seconds at a time with only seconds in between.

If you have any more episodes go straight to hospital so they can catch and record it, I wish I'd done it years ago! It was only because I blacked out at work in front of a new boss that I ended up in a and e in May. She said I convulsed, head back, eyes spinning mouth open and then hit the floor. It was her that said that's no panic attack.

Feel free to send me messages you're not alone I promise! X


Bless! That sounds horrific. Yes, i will, and thanks, knowing someone has an idea of how you feel helps so much, and that you can communicate with someone who cares is invaluable. Wishes of good health to you.

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Thank you for posting this....

I had a similar experience which has been picked up on my pacemaker readouts but which my cardiologists have not been able to explain.

It happened to me under stress two to three times. I seemed to "blank out" - standing, but unable to speak, react, move momentarily. It got dismissed as "anxiety" at the time.

No idea what my heart was up to at the time and no explanation from the cardiologists apart from to tell me that there was something "seriously wrong".

It hasn't happened since the stress has stopped.

I also had brief convulsive activity on a tilt table (years ago) when my heart stopped and then re-started....but that made more sense as my heart stopped which I imagine would cause this kind of reaction.

Periods of blanking and confusion are linked to the progression of sinus node disease which I've recently been diagnosed with, but I had a pacemaker in place when I had the "blanking out" which I would have thought would correct this!

I developed atrial tachycardia a while ago. I'd like to know if this is the cause but have come up against shrugged shoulders from the medical profession.

Sorry can't clarify or help....but I can, at least, empathise.


The empathy is valuable as you i'm sure know! Hopelessness is literally lethal, i'm banking up all the little bits of caring i get and offsetting my frustration and impatience to see the ep with it. Cannot understand how i can't even get a reply of what month it might be! 'They' just don't get how this condition (whatever that might be in the broad spectrum of heart arrhythymia) can make you feel. All my energy is going into not staying in bed all day and not worrying myself sicker, even if it does mean putting a pencil between my teeth to fake a smile and stimulate brain chemicals - this is one of those wee tricks that strangely seems to have an effect - and also the act of doing it makes me smile! It's a little thing, but the more little things i actively do, the less hopeless i feel! Thanks for taking the time to give me a little more info and to boost me a little. Wishing you a strong and steady heartbeat!


Keep in touch xxx


Hi Stargazer 61!

I feel like I was diagnosed with all of those things by my neurologist...TIAs for having face tingling and slight numbness on the right side in March, episodes of near syncope, and a syncope episode driving when I pulled over and hit my face as tunnel vision started. Luckily my friend lived nearby so I drove right to her house. My cardiologist said to go to my Neurologist (still in March) and he ran CT scan of head-Negative. Later on 3/31 he ran CT of head and neck blood flow...luckily no obstruction, clots, or problems with that either. So Neuro diagnosed me with TIA episodes based on : Tunnel vision, right-sided facial numbness that lasted 6 weeks, right sided weakness that was short lived, and episodic tingling on right side with about 3 episodes of near syncope with right sided aura. Done. Diagnosis, 3 episodes of TIA. Then in April I went to the ER because I was driving and stopped at a red stop light for several seconds...woke up with my head slumped way down on my chest and I had a very hard time getting back up. The light was still red for 5 more secs, my pulse was pretty normal and my eyes looked OK...I had passed out cold and I had a bruise on my chin. I already have a CRT-D implanted in 8-12-2012, and was diagnose with CHF (suddenly)in 2011, but I never had this. So I already have an EP, and he met me after 12 hrs in the ER. The Medtronic tech and he was able to pinpoint the SVTs (and PVTs were going on all night during observation) so he wanted to do an ablation, EP study, and Right Heart Cath but during the procedure , which took 3 heart was tired and slow and would not do any arrhythmias for him. Basically it was found that over the past couple of years my initial LBBB had progress to high-grade AV block so I am 100% paced anyway! Nothing more can really be done that isn't already being done...Who knew!

So if you haven't had any CT scans or meetings with Neurologists or whatever (I'm in the USA and go to University of Chicago, and the Ablation was a fail for me but the EP study and Heart CATH yielded SO MUCH INFO!!!!

I would say if your heart is going 300 bpm MY GOD PLEASE HAVE THE ABLATION or AT LEAST AN EP STUDY! GUARANTEED they will do one whilst they are in there!!!! Why would you cancel it with THOSE SYMPTOMS??? Please I'm only saying it for your heart's sake! I have had so much wear and tear on my  heart I am headed for complete heart block now....and I would have never known it if my EP didn't step up and DO SOMETHING! Just be brave and reschedule! Ask for an extra sedative and jump in...Maybe your heart will chicken out like mine did (LOL) and all he'll do is an EP study and a RT & LT Heart Cath! See if you can get in touch with his nurse or something ahead of time and ask if this can be done first before the ablation while they are in there, they are going to need this information anyway! You deserve the info too! Good luck! I've been going thru this for 5 years and i've gotten crusty and want to know everything, but I feel for YOU and I have gone thru bad things too, trust me. Prayers and hugs! Plz keep me posted! I care!  LOVE!!!! <3


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