Inapropriate Sinus Tachycardia as a symptom?

Hi, has anyone had a Dysautonomia condition diagnosed where IST (inapropriate sinus tachycrdia) was atcually a symptom? My cardiologist thinks I may have IST but not all my symptoms and ecg results fit with this.

Many thanks

[sweetwoman23]

Hello sheshez

I think there could be many causes for sinus tachycardia ( I have it too)

Have you been checked for hyperthyroidism or problems with your adrenal glands?

yours

sweetwoman :)

[Heiferly]

I don't think I'm understanding your question correctly.  Are you asking if sinus tachycardia can be a symptom of another form of dysautonomia OTHER THAN the diagnosis of Inappropriate Sinus Tachycardia Itself?  E.g.., could a person diagnosed with Postural Orthostatic Tachycardia Syndrome as their actual *diagnosis* have "inappropriate sinus tachycardia" listed as a symptom of their POTS?

-OR-

Are you asking can Inappropriate Sinus Tachycardia be a diagnosis unto itself, even if other symptoms are present and/or the sinus tach is not constant?

-OR-

Are you asking something else entirely and I'm just totally missing the boat?

(I apologize, this may be a major brain fog moment for me, but I'm just not "getting it" right now.)

I'll try to give you a few different answers, you go ahead and shoot me back and response and tell me if i managed to hit it somewhere in here or missed the boat entirely, okay?  LOL

1.  Many patients with various dysautonomia diagnoses do display "inappropriate sinus tachycardia" from time to time.  To put that more concretely, POTS patients by the book would only have tachycardia in upright postures, but I have yet to meet one who has NEVER had IST here and there whilst supine.  Dysautonomia is a bit unpredictable like that and the lines are a lot more GRAY than textbook definitions would have us believe.  It's a spectrum; it gets more complicated when a patient reaches closer to the end of the spectrum where they might, for example, fit the diagnostic criterion for BOTH POTS and IST.  Some doctors with diagnose both disorders concurrently; others will choose one diagnosis to be the primary diagnosis and list the other "diagnosis" not as a diagnosis but as a "feature" of the primary diagnosis, or put otherwise, as a symptoms.  Yes, it's a hot mess, there's no consistency, no one is writing the rules here, and some doctors decided to just leave it at "dysautonomia" to spare the struggle.  I used to balk at that, but I don't any longer after watching us all try to compare diagnostic labels in vain.  

2.  Inappropriate sinus tachycardia is often extremely difficult to distinguish from other forms of dysautonomia.  This medical journal article does an excellent job of explaining the differential diagnosis of sinus tachycardias (pdf will download immediately--sorry I can't find an indirect link):

http://www.iranep.org/Articles/Sinus%20tach%20GP%20Clin%20Cardiol%202005.pdf

If I've missed your question entirely, please fire away again and I'll take another shot again.  Also, if you'd like to know more about your concerns about your diagnosis, it may be helpful to share with us what tests you've had so far and what the results of those have been (in as much detail as you know--such that "HR rose 37 BPM to 121 and BP dropped to a low of 74/58 before table was lowered as I was nearing fainting on the tilt table test, which was considered a 'positive' result for POTS" is much more useful than "tilt was positive").  

Sorry again for my brain fogginess today,
Heiferly.

[tonyad]

    Hi there. I understand what you are asking and totally know what you are talking about!

    I was dx withn IST Last year and I KNEW in my heart (no pun intended) that was not what I had and my Regular Cardiologist agreed.

    Flash foreward (sp) ...My Cardiologist refferred (sp) me to a different ElectroPhysiologist and yes..another TTT done.......and GUess What...NOT IST but rather NCS (NeuroCardioGenic syncope)...Yes...that fits Much better!

    How where you diagnised? Through TTT (Tilt Table Test)?   if you do not feel comfortable with this dx (I did not) then I would get a second opinion!

    Are you on meds now?  With both you need to stay WELL Hydrated, increase Sodium Intake, Do NOT get Overheated, Compression Stockings (have to admit I do not wear mine much).
    
      Do you have actual episodes where you PASS OUT or just Nearly pass out?
Can you tell when the syncope is starting?  

~Tonya

[Heiferly]

Taking a second look at your post, and reviewing former posts that you have made in other forums, I do have some additional input.  I see that you have some significant dysrrhythmias aside from IST that have been picked up on ECG monitoring which seem likely indicative of either something in addition to or other than IST being present in your case.  Because you are "across the pond," the person here on the forum that I would be most interested in seeing you connect with is one of our members with the username "evo123"--you can find her in the sidebar on the right hand side of this page in the "Top Arrhythmias Answerers" box and if you click on her name you can send her a direct message.  She's the one member of our forum that I know of that's outside the US and is more familiar with the healthcare system on your side of things.  The reason I mention this is to get to the point that you might benefit from pursuing an appointment with a dysautonomia specialist if it's not too geographically far from where you live, and she can tell you more about how that works over there.  A dysautonomia specialist might be able to help your electrophysiologist tease out your cardiac issues from what is a possible case of IST (or possibly another form of orthostatic intolerance dysautonomia).  

I apologize that I'm not terribly familiar with the UK system myself, but hopefully evo123 can give you some guidance if you get in contact with her, or she sees this post here.  

Do you know the diagnostic criterion for POTS and/or NCS vs. IST?  If you want us to give you more information on what the differences between those types of dysautonomia are, we can certainly point you to that information.  I suspect that at the moment, though, your concern centers more on the diagnosing IST despite the other abnormalities on your ECG which are not sinus tach.  If that is the case, it might help to have an electrophysiologist who sub-specializes in syncope/dysautonomia on your case, but I don't know who that would be where you live.  Maybe evo123 knows if Dr. Mathias is the equivalent of that?  I've seen him listed in the department of "neurovascular medicine," but I don't know if that makes him a neurologist, a cardiovascular doc, or both???  

Sorry Tonya, but I have to disagree with you on recommending sodium-loading.  Sheshez, because you have these other cardiac arrhythmias, I do not recommend any dietary/lifestyle changes without first consulting your cardiologist/electrophysiologist.  If your doctor would like you to go on an increased sodium/hydration diet, made sure you get guidelines on how many mg of sodium per day you should be consuming.  Because you may be dealing with distinctly different issues than "just" dysautonomia/IST, you may have to follow different guidelines than other members of this forum when it comes to these recommendations so double-check with your doctor before taking any advice you see here!

I'm sorry to hear about the symptomatic bradycardia you had with your medication as well (from reading your earlier post).  I hope that you have worked that out with your doctor so that you're on a comfortable dose that controls your tachycardia, but doesn't drive your HR down uncomfortably low.  Many of the members of this forum have had experiences with mild bradycardia where it wasn't low enough to be "dangerous," but was uncomfortable or caused some symptoms.  No fun!  I know several of us haven't been able to tolerate beta blockers for that reason.  

[Sheshez]

Hi everyone, thanks so much for your comments, I will try to answer all of your questions in order. I have being feeling really rather lost and isolated of this lately so it really is lovely to have people to discuss this.

1. What I actually ment was is it possible to have IST as a symptom of something else? i.e POTS (not that I know very much abt this).

2. My Thyroid is fine, I did syggest my GP did a 24hr urine test to look at my adrenal glands but he did not think it was necessary ? because the baseline bloods he took where all ok, this was back last October mind you)

3. This all started last August and has progressively gotten worse, I currently experience many palpitations daily, dizziness/giddiness, shortness of breath on exertion, feeling faint (and I have actually fainting twice), lightheadedness when I stand up (although not aways), chest discomfort/mild pain and occasionally being woken from sleep with massive jolts to my heart.

I have had numerous ecgs, a 24 hr tape - showed tachycardia consistant with symptoms and inverted T waves, CXR - normal as far as I know, echocardiogram - normal, blood tests - normal. I have just had to wear a cardiac event monitor for a week but do not yet have the results and am due to have an excercise tolerance test in abt 2 weeks time. No one has really worried abt my BP, it has always been in normal range although I did have a spell abt 18months ago when it was different in each arm but the no clear cause was ever found, it is fine now.

4. I have not yet been officially diagnosed but both my cardiologist and electrophysican feel that this is the very likely diagnosis as it fits with my symptoms, however I have also just found out in addition to inverted T waves and ST segment shift (sometimes flattened sometimes depressed); that I have Incomplete right bundle branch block, which I am told is harmless and may explain my Inverted T waves? (a nurse told me this not a physican).

I think the plan is that I am to have the cardiac monitor test and ETT and if that does not show up any dangerous arrrythmias or any other cause of my symptoms, it will be assumed I have IST and I will be put on a new calcium blocker and have the option of cardiac ablation for the serverity of my symptoms. I have never been offered a TTT.

5. You right Tonya, I am not completely convinced by the diagnosis of IST.

6. I am currently on a betablocker, bisoprolol 1.25 - 2.5mg.

7. I have fainted twice, but more often then not just feel faint but not so faint that I think I am going to pass out that has only happened twice and then I did!

8. I am afraid I know very little abt POTS or any other dysautonomia condition but have just read that IST and some of these conditions may be linked

Thank you so much for taking the time to help me

Kind regards Shel

[Heiferly]

Shel,

I'm rather ill today myself and unable to put together a very comprehensive response, but I will get back to you more thoroughly when I'm able.  I do feel it prudent to at least put this one thing out there though, in the meantime:  while ablation can be immensely helpful if it is the correct treatment for the correct diagnosis, it can be harmful if done under false pretense.  If it happens to be the case that they're missing the mark on your diagnosis right now (and if you read the journal article I linked for you, you can see how easily IST and POTS are to mix up ... MANY cases of POTS or other OI-forms of dysautonomia are initially (mis-) diagnosed as IST), going through with an ablation could be an irreversible mistake.  When I'm feeling better and get back to you, hopefully I can find the article I have saved on my computer that specifically talks about cardiac ablation being harmful/contra-indicated for the many (most?) patients with postural orthostatic tachycardia syndromes.  If I were you I would definitely be pursuing a tilt table test aggressively at this point; there's absolutely no reason they shouldn't be ruling out NCS and/or POTS before definitively diagnosing IST in light of your symptoms, particularly your history of syncope.

I'll get back to you as soon as I'm able to tolerate being upright a bit longer,
good luck with the upcoming testing!  
-H.

[Sheshez]

Hi Heiferly

I am so sorry to hear you are struggling today but thank you so much fo the time you have given me, I did read the article and can now see exactly what you mean, I have written a list of questions to ask my EP when I see him next as a result of everyones advice.

Take care and get well soon!
Shel

[evo123]

Hiya, I am sorry to hear you are experiencing these symptoms and are, like many here, struggling to find a correct diagnosis.  I will try my best to help you and give you my support.  I am sorry I have not seen this post sooner I am having a bad few days so bare with me if you find I am rambling!!  x  

From what I know about IST it is a diagnosis of exclusion. Sinus tachycardia is more commonly appropriate. So, in turn, causes of appropriate sinus tachycardia must first be excluded.  I believe it only becomes inappropriate when a cause cannot be found. (hope that makes sense!!)  

I can see from your posts that you have had many cardiac tests done, but I strongly suggest you push for further testing than the ones that you have mentioned are scheduled.  As Heiferly has stated I also believe that a Tilt Table Test is an important next step for you.  This will see if there are any postural implications to your symptoms and could possibly rule in or out another diagnosis.  I have POTS and mostly experience tachycardia when upright but do, on a regular basis, experience it regardless of my position/posture.  

I would also strongly recommend you have a full workup of your adrenal glands.  A differential doagnosis for IST is Pheochromocytoma, although this to is very rare (it is also a differential for POTS), This will not show up in baseline bloods, specific tests need to be ordered to test for this.  Most adrenal hormones need specific tests carried out to evaluate their function, I do not believe these would show up on everyday bloods.  I was a Phlebotomist for the NHS before I became to unwell to work any longer and it was my job to carry out the usual blood testing and I never came across any of the tests I believe you need in my clinic as these are (in my area) tests that are carried out in a hospital setting.  Also, several of these tests need 24hr urine collection as you seem to be aware.  

I struggled for a dx to and I found that requesting a copy of my medical records was helpful for me in the respect that I could see what tests had been carried out and what their results were.  If you would like advice on how to go about doing this in the UK PM and I will help you.  

I see from your posts that you have inverted T waves.  I have these also and have been assured by my cardiologist that this is nothing to worry about, when I recieved copies of my medical notes I also seen on a few of my ECG's that my QT interval was lengthened.  I have read from your posts that this is the case with you to.  Nothing has been done for me in relation to this and my cardiologist shows no concern as this is not consistant but I do not know enough about this yet to advise, it is good that your cardio has had you on a tape for a week, please let us know the results.  

I agree with Heiferly when she advises against increasing your sodium intake, I would hold off on this until your get a final dx and serious arrythmia is ruled out.  By all means increase your fluids, stay cool and give compression stockings a try x

Has a loop recorder ever been mentioned for you.  This is a small device fitted in the chest area and it can help with diagnosis.  Maybe this is something you can talk about with your doctors if you feel it may help them with a correct dx.  Others here will have more info on this for you if you are interested in finding out about it.

I have found it extremely hard to get to see a doctor who specializes in dysautonomia and related conditions.  I have had to push to see Professor Mathias who is one of the UK's limited number of specialists in these conditions.   I believe him to be the leading autonomic specialist here.  'Professor Mathias is Clinical Service and Research Director of two departments specialising in autonomic and neurovascular disorders, the Neurovascular Medicine Unit at St Mary's Hospital and the Autonomic Unit at the National Hospital for Neurology and Neurosurgery, Queen Square, London. Both are tertiary referral centres for the entire country, with a number of referrals from Europe and worldwide' (taken from http://www1.imperial.ac.uk/medicine/people/c.mathias/).  I have contact details for him if you would like them, he can be seen in Queens Square on the NHS.  You will need a referral from your consultant and he/she would need authorization from your local primary care trust (I can help advise you on this), or you can see him privately at St. Mary's which is a lot quicker but can be expensive.  I have not long had an appointment with him and he is lovely and seems to totally understand (which is not common with these types of illnesses) so I would definately recommend him.  I live in the North West so I do have to travel to see him but it is definately worth the journey.  

I will also advise against accepting ablation treatment whilst you do not have a confirmed dx as I to have read that in certain forms of dysautonomia this can worsen symptoms.  

In your post above you mention that predominately your bp is fine, I am assuming you have had laying and standing BP checks to see how your bp reacts to position change.  My bp is nearly always fine when sitting (and that is how bp is usually taken) but lay me down and it lowers, and stand me up and it rockets.  If you have not had observation of how your bp values in these positions it would be wise to do so.   It would also be helpful if you know what happens to your heart rate with position change.  Maybe you could post some of your values here and we can see if there is any change.


I hope this helps you and you are soon nearer to finding out what is going on with you.  In the meantime we, as a community here on medhelp, are here to support you and offer any help we can x

[gwcurt]

I was consistently running a heart beat of 110 to 150. They were able to control BP, but couldn't do anything with HR.  Their were times when I felt weak and dizzy that I know now my BP was low.  8 months ago I crashed. BP went down to 80/40 , HR 49. Stayed that way for about a day.  This crash according to cardiologist was due to autonomic neuropathy. Since the crash BP fluctuates, but HR stays between 55-65.  So I guess our control mechanism can change from time to time.  Good Luck

[Heiferly]

Gwcurt,

Are you being treated specifically for your dysautonomia?  There are medications that can help with hypotension from secondary dysautonomia due to autonomic neuropathy.  Admittedly (like everything else, I'm sure you understand), they work more for some patients than for others, and it's a lot of trial and error ... but it may be worth a shot if you haven't given it a try.  Also, though they're far from glamorous or particularly comfortable, many find prescription compression stockings to be helpful.  You may want to discuss these options with your cardiologist if s/he hasn't mentioned them already and you're battling symptoms from the dysautonomia.

[Heiferly]

Thanks a million bucks, er ... what's it over there? ... pounds??  LOL  I KNEW you'd have our backs on this one!!!  Sorry you're having a rough time of it right now.  Ugh!  What is it?  It must be the change in seasons, right?  I had THE MOST EMBARASSING faint at Mr. McDreamy's parents' house the other night.  Yep, I'm officially the worst dinner guest EVAR.  :-p  I guess it's the witching hour for all of us right now, because from the looks of it, we're dropping like flies around here.  At any rate, thanks soooo much for covering this one with your specialized UK expertise.  Me and my "never traveled further outside the US than Canada" worldliness was just not cutting it, lol.  

Have a fabulous mother's day and hug those gorgeous angels for me!!!

[Sheshez]

Thank you so much Evo123 (and Heiferly for reccomending you!), I am going to defaintly make sure that both my cardiologist and EP are 100% sure that there is nothing else going on here before they even get me on the table for ablation!, I plan to ask for  TTT, magnesium Blood test and also Adrenal gland workup (thats assuming the results of my 7 day monitor or ETT dosen't show up anything obvious in the mean time), I am also going to experiment with my BP ( sitting, standing and laying) to see if there are any significant difference here.

I do hope that you start to feel better soon and thanks again, you have all been a huge help to me! :) x

[Sheshez]

Hi, thanks so much for you input, gosh that must have been really scary to have such a crash! are things more controlled for you now? Shel

[evo123]

Hi, if you are going to give it a go at home and see what happens to your bp in the mentioned positions, take note of your heart rate at the same time.  This will give you a  better idea of things.  

Glad we can help you x Heiferly is great and has an extensive knowledge on many conditions relating to dysautonomia, her and Halbashes (another community leader here) have got so many people here through the dx process, including myself.  This is a great community with supportive members x

[evo123]

Hiya x Thank you for recommending me and I am glad my input has been helpful x

Yeah...over here it is ££££ - not that they are worth much at the moment!!!! lol x  Funnily enough though we still use the saying a million dollars!!!

My cardio has increased my Fludrocortisone back up to 200mcg again and I am now constantly lightheaded (again!!!), he wants me to take this full dose in the morning but I am a bit wary of this so am taking 100mcg in the morning and the other 100mcg in the afternoon!!  and yeah I think the weather may have something to do with this too!!!  (boohoo).  He is putting me on different beta blockers I am just waiting for my prescription, I can't remember which ones he wants to try - I was having a really fuzzy day!  But he did say he wants me to try and stick with them for a couple of months even if the side effects are bad!!  So I will let you know.

Hope you are okay....and when you do venture outside the US you are welcome here for dinner....and we wont mind if you faint on us!!!!! Lol x  I hope you didn't hurt yourself when you fainted and that your Mr McDreamy broke your fall xx

[LivingInHope]

I was diagnosed with IST and later, by tilt table test, I was diagnosed with POTS.  If I'm recalling what I have read in the past correctly, it is possible to faint with POTS, but a lot of people don't with that diagnosis.  The only time I ever fainted was during the tilt table test after they gave me nitroglycerine under my tongue and tilted me up.  

While you are waiting to  be seen, you might go out if you don't have a blood pressure monitor (that does pulse too) already and pick up an omron or other highly recommended brand and do a little testing yourself.  Like, lay for 10 minutes and take your blood pressure and pulse.  Then stand for 2-3 minutes and take your blood pressure and pulse again.  When you stand, you may have to take a radial pulse (with your pointer and middle finger on your wrist below your thumb) for 15 seconds and multiply by four for your heart rate, because the machine doesn't always get it right!  You can wait until 10 minutes of standing and try it again too.  

In POTS, it was explained to me by an electrophysiologist, my heart was racing when standing so that I wouldn't pass out.  For me, I've had evidence that my catecholamines have gone into overdrive with my POTS, but with a fasting blood test called plasma free metanephrines, which is supposed to be the best test there is for detecting that rare tumor evo spoke of called a pheochromocytoma, they ruled out that kind of tumor.  You have to avoid tylenol for either 48 or 72 hours (not sure which) prior to the test or it can interfere with assaying the levels.  Pheochromocytomas can have silent periods, where they are not emitting high levels of catecholamine- so you would want to get the test in  a time frame when your tachycardia symptoms are particularly bad.

And please get your ferritin and iron tested, because low levels of these, even with a normal CBC, can make your tachycardia even worse!

[Sheshez]

Hi there

Thank you so much for you kind advice, especially ther name of the blood test I would specifically need. I will investigate my BP and let you all now how I get on.

Many thanks again
Shel