Dysautonomia (Autonomic Dysfunction) Community
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Avatar universal

Inappropriate Sinus Tachycardia and Exercise

Hello! I am a 26 year old female with inappropriate sinus tachycardia (IST), displaying all symptoms. I recently had an EP study because my electrophysiologist was hoping that I had right atrial tachycardia and wanted to ablate me. The procedure was unsuccessful and they did not find any locations to ablate. Thus the thinking is IST.

I understand that very little is known about IST and how to treat it. I am currently not taking beta blockers, though I have in the past.

I have a very high intolerance to exercise. I would like to start an exercise routine that will get me toned and back into shape, but without risking something happening to my heart.

I am 130lbs, 5'5" and my scale says 26% muscle and 33% body fat. Once upon a time I was in much better shape - I was always one of those girls that ate like a cow and never gained a pound over 100lbs (I have a small frame).

The last time I went running was about 8 or 9 months ago. Back then my resting heart rate was about 105. I was still taking beta blockers and my heart rate would rise to 150 within the first couple minutes of running. My peak rate would be over 195 after 10 minutes or so and I would stop.

Currently my resting heart rate is 120 and my heart rate rises to 150 upon simply walking around. Is it safe for me to start running again? Are there other forms of exercise I should do instead? How high should I let my heart rate get before slowing to a walking pace?

Any other tips/advice would be greatly appreciated!
10 Responses
612876 tn?1355518095
There's a test called a cardiopulmonary stress test that can be used to assess your peak "VO2" and "MET" levels.  Sorry, I am really sick tonight and don't have enough strength left to stay up and explain this but I will post more as soon as I'm able.  You can also try googling these terms, or calling your cardiologist and asking about the test.  This test can likely pinpoint a target range that is ideal for you to safely exercise within.  

Will get back to you soon I hope.  Sorry to be so brief,
612876 tn?1355518095
Sorry for the delay, but here's a URL that gives the gist of what a cardiopulmonary stress test is:


Why did your doctor take you off the beta blocker, and what are you taking now?  Is your doctor concerned about your resting heart rate of 120?  

I have an excellent article on the differential diagnosis of IST if you are interested in reading it.  It is a medical journal article (i.e., not written for laypersons) but if I recall correctly it's not a terribly difficult read, relatively speaking.  At the least, you might want to share it with your doctors if they're still having any doubts about your diagnosis or you think it might help them understand your case better.  

Your exercise intolerance is an issue, and I can certainly give you tips on how that would typically be addressed in a rehabilitation setting (has your doctor considered physical therapy or cardiac rehabilitation to address your exercise intolerance?) but in my opinion, it seems as though your primary issue at the moment is getting your resting heart rate back under control.  

Maybe if you tell us more about what your treatment regimen is and what track your doctor is taking we can have a clearer idea of what's going on.
Avatar universal
Thanks for responding! I did have a stress EKG, but not the cardiopulmonary stress test. I will discuss that with my electrophysiologist.

My doctor took me off the metoprolol for my EP study. They told me recently via phone I could go back on it but I want to wait until after my next doctor appointment to discuss with him. The metoprolol was helping at first but after a few months my body got used to it and it wasn't helping anymore. I'm a little concerned about higher dosage becuase it was already lowering my blood pressure a bit. So, right now I'm not taking anything. I don't really know what the doctors are thinking because my EP study was in January and my follow up appointment is not until March. They basically said they weren't sure what to do when I was in the hospital after the EP study.

I'd love to read the article you are referring to. I have a science degree and generally can understand medical journal articles (I actually would rather read these than websites to get to the real science behind everything!)

Regarding the physical therapy/cardiac rehabilitation - it has not been discussed yet, but one of the fellows mentioned the possibility of a crazy bootcamp-like regimen of exercise (yikes!).

Recently I tried to begin running again (more jogging actually). I average around a 13.5 minute mile. My heart rate seems to average around 170-180. But after a mile, spikes begin and my rate jumps to 210-240+. I slow to a walk until it drops back to 160-165 and then start jogging again and after about 5 steps it is back over 210 and I'm back to walking. Very frustrating.

I know not much is really known about IST, but if there was some way to determine the cause rather than just treat/mask the symptoms, I would be so happy. Next doctor appointment is March 7 - I can post an update then. In the meantime, if you have any more thoughts, I'd love to hear them! Thank you SO much!
612876 tn?1355518095
Here is my favorite journal article for IST folks:

(google docs view; sorry, really ugly URL)


(Direct link to the pdf of same, will begin download immediately; sorry, I provided google docs URL because I don't have anything else indirect.)


By the way, hello fellow science person!!  I never thought I would be so thankful for all those "hard science" classes until I got sick with dysautonomia and ended up working towards my "honorary degree" in ... well, I doubt you can get a degree just in the ANS, but if you could ... I'm well on my way toward my honorary degree!  :-p  

Sorry, back to the task at hand.  I also pulled out one of my trusty textbooks for you; it appears that IST is covered on p. 2170 of _Cardiovascular Medicine_ (Willerson, Cohn, Wellens, and Holmes Jr., eds).  Lest you think I'm joking, I had a tough choice between breaking my wrist or breaking a toe if I dropped this hefty tome whilst trying to fish it off the bookshelf a minute ago (*really* should have used two hands or not reached over a piece of furniture), but no that's not a typo on the page number.  And NO, I absolutely have not read this one cover-to-cover.  :-D


Essentially, the textbook says that the treatment options known to these authors are calcium channel blockers, beta blockers, or surgery "to ablate or isolate the sinoatrial node."  They give a bit more detail on expected outcome from pharmacological treatment:  "however, medical management often leads only to transient relief." (Which seems to have been your experience as well?)  They also give some limited statistics and anecdotal reports on surgical outcomes, but they look a little outdated to me even though this text was published "only" four years ago.  ... If they're going off data that is "only" a few years old in the text, add that to the few years old that my text is and ... well, yeah, it seems outdated from what I can tell compared to the "bleeding edge" stuff that can be found in journal articles.  

If you haven't used google scholar to mine journal articles yet, you might try that (here's your base search, you can refine from here using the drop-downs or adding search terms):


Let me know if there's anything else I can look up for you.  Unfortunately there's not much in the textbooks on IST.  Judging by my collection, you'll have more luck in cardiology texts than in autonomic or neurology textbooks as it seems to get mentioned in passing as a differential dx in autonomic textbooks, if that.  Unfortunately, in my home "library," I have just this one tome when it comes to straight-up cardiology texts.

I'll keep you posted if I come across anything else that I think would be useful to you.  In the meantime, let me know if there's anything else I can do/find for you, and please do keep me updated on what goes on with you!  Take good care of yourself!!
Avatar universal
Hi there!

I have the exact same problem as you, and I'm the same age. Did you ever get a resolution? Can you now exercise? I was diagnosed with IST at 15 years old and have been afraid to exercise because of this problem, but I'm sick of not being in shape.

Thank you!!
Avatar universal
If the underlying cause of your IST is low blood pressure or hypovolemia/dehydration, drinking a lot of fluids should bring your heart rate down. Make sure you're properly hydrated. I alternate homemade oral rehydration fluids with water.
Avatar universal

I never did find a resolution to my IST, although like most IST cases, the symptoms have started to improve over time. I started exercising regularly, with difficulty, but my resting rate (lying down) is now around 80-85 and sitting up ~85-95. Big improvement! My current weight is 125 lbs, muscle 28 percent and fat 29 percent. Small improvement there but it's something! I have had many hiccups in the exercise routine (injuries, laziness, etc) but getting into a set routine takes work and practice makes perfect! I'll keep trying :)

I think one of the most important things I did was get out of a bad work situation. I am exceptionally sensitive to stress, which is likely related to whatever causes the IST. Upon relieving this stress, many of my symptoms improved to some degree.

Making sure to take care of myself mentally and physically has been really important. I eat a healthy diet, I exercise, I rest (big one!), I stay hydrated (not always good about this one...), and I avoid unnecessary negative situations that cause the mind and body stress.

Good luck to you! I'm happy to share any more of my experience with you if you have any more questions. Keep your chin up and give working out a go. Make sure to do a good balance of cardio and strength training. My electrophysiologist was quite renowned and assured me that exercise could only help and not hurt. Of course, check with your doctor too...
Avatar universal
  I am 60 years old, i have had IST  all my life  as did my father. when I was first diagnosed I was pregnant with my first child  (1978) my Dr told me if my heart was going to be a problem this pregnancy would find it out. I gave no thought to it and went on to have 2 more children.  i was always the reader , all sports were beyond my ability,      i was much bullied and never felt to be in the group  so to say  
fast forward... my kids are teenagers  my husband has lost his job, my job wouldn't last unless we moved from Missouri to Connecticut
I was  under a lot stress and i end up in the hosp. with heart failed my E.F. was30%   to make this short i have been from 15-40%over the last 6 years.....I now have an implanted defibrillator     And not one of my Dr.s have given me the permission to enroll in cardiac rehab

WHY i dont get it i can barely walk to get my mail!!!!!!HELP

Avatar universal
hi i am 26yrs old and diagnosed with IST after about a month of test. i was told by my cardiologist today if i feel ok excersize by all means but if anytime during the excersize i become symptomatic then stop. i am also a nurse and i think generally we also go by if patients are symptomatic or not but by all means i am not a expert but good luck with getting in shape and hope all goes well
Avatar universal
Hello I am a 28  year old female and alsho dealing with this..I just had an EP study because they thought it was SVT, but we're not able to reproduce it. I have had a lot of the symptoms and some hard to distinguish. Currently taking metoprolol but my doc will be taking me off that soon and trying something else. I am also nervous about exercising. But I agree, that and stress relief could help. I really don't want to be on medication if not needed and now I'm nervous to try any recommended treatments. I have already changed my diet. Just looking into the IST.
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