Inappropriate Sinus Tachycardia & Ivabradine?

Posted , 3 users are following.

Hi guys! 

Im a 20yr old female so had an ablation aug 1st for SVT. Since then I have been SVT free! Woohoo! 

But I have also been diagnosed with IST since then, and have been struggling to manage. I was diagnosed 4 days ago, and was prescribed Ivabradine for it with promising results. I have also been tested for POTS & I do not have that. My symptoms are constant lightheadedness, racing heart rate with minimal exertion and fatigue. However I do have a normal heart rate while resting but it does skyrocket with minimal exertion. I have symptoms regardless of my heart rate(symptoms are more intense with higher HR) but my electrophysiologist believes it is from my prolonged IST that has caused some damage to my system. Any thoughts? Anyone with IST? Is it normal to have symptoms with normal HR? Anyone on IVabradine? 

Thank you! 

0 likes, 6 replies

Report / Delete

6 Replies

  • Posted

    Hi, did you have this before your ablation?, were you on beta-blockers before your ablation?

    I haven't been diagnosed yet, but am being investigated for as since my ablation for Ventricular Tachycardia, my heart rate is all over the place, but mainly much higher than it was, doing nothing it is often high 90s, then at other times it is in 40s. Gentle walking it varies between 40s then shoots up to 180s for no reason, but generally it is over 100.

    I have complete exhaustion and a blood oxygen rate that can be 99% but can also be as low as 85%, it is as if my automatic systems have gone a little haywire since taking beta-blockers and then my ablation.


    Report / Delete Reply
    • Posted


      My specialist assumes that I had this prior to my ablation, but because of poor knowledge of the doctors I had seen, they all diagnosed it as anxiety. So because I was put under the anxiety rock, it was never fully investigated and managed before my ablation. So he thinks my ablation aggravated my IST. My heart rate was always sensitive to movement, and he thought I had POTS but it doesn’t increase with standing- only movement. I wasn’t put on beta blockers because the doctors unfortunately brushed off my condition until I had my first documented SVT. But now he believes the Ivabradine will be a success controlling my heart rate and relieving my constant lightheadedness! I start tomorrow. Completely excited but it was a struggle to get my hands on these medications as it’s pretty new and most pharamicies did not have them available right away in Canada. 

      I know that if they ablate near the nerve that controls breathing/nerve related to the lungs - it can affect your oxygen levels and lung efficiency. (Correct me if I’m wrong- from what I learned) also I did hear beta blockers can cause more damage then good... I have learned from these forums & because I am only 20 my specialist doesn’t want to start roughly. My max heart rate during walking around a mall for example runs up to about 140bpm. But my resting heart rate runs around 80.

      You have probably already investigated these issues but it’s worth a shot to mention; 






      A lot of secondary conditions can contribute to a unregulated heart rate - I noticed if I Take magnesium every night before bed - not only do I sleep like a baby, but I am rested and my heart rate is regulated for atleast 6 hours after waking. 

      How’s your blood pressure?

      Have you heard of POTS? 

      Report / Delete Reply
    • Posted

      Hi Megan, you wrote "I know that if they ablate near the nerve that controls breathing/nerve related to the lungs - it can affect your oxygen levels and lung efficiency.", where did you hear this?, do you have a link please? This would be very helpful to tell my cardiologist.

      I don't have POTS, I have heart rate monitors and they don't show a change when I stand up.

      I have been told my blood pressure is "perfect".

      You are lucky to have avoided beta-blockers.

      Hope this new med helps.

      Report / Delete Reply
    • Posted

      Hi Peter, 

      Here are some useful links. It mainly talks about ablation with AF, now depending on where they ablated - it can happen with any ablation procedure if they ablate near the nerve.

      And another one

      I hope these links are helpful! Keep us updated with any progress or information! 


      Report / Delete Reply
    • Posted

      Hi Megan, I saw my cardiologist on Tuesday and mentioned damage to the Autonomic Nervous System following an ablation, he assured me my ablation was nowhere near a nerve, My problems started when I went on beta-blockers for a while rather than the ablation, I pointed this out but they dont want to hear their drugs can cause damage, so he wants me to see a psychiatrist next! 
      Report / Delete Reply
  • Posted

    I'm 30 and your case sounds very familiar to mine.  I have ARVD and had my SVT ablated in 2011.  I developed VT due to my AV Node and that was ablated a few months ago in Oct '17.  Since then I developed IST.  My doctors are wanting me to start Ivabradine but my insurance keeps denying it.  My doctor at Johns Hopkins, after consulting other physicians, discussed removing a certain nerve. (He just told me about this and do not have all the technical information quite yet regarding it).  He said it's not an actual heart issue but rather a nerve issue.  It sucks though b/c I'm with you, I can hardly walk anywhere, change sheets, clean etc. without a high HR and with an ICD I'm afraid of getting shocked.  I know where your coming from!  

    Report / Delete Reply

Join this discussion or start a new one?

New discussion Reply

Report or request deletion

Thanks for your help!

We want the forums to be a useful resource for our users but it is important to remember that the forums are not moderated or reviewed by doctors and so you should not rely on opinions or advice given by other users in respect of any healthcare matters. Always speak to your doctor before acting and in cases of emergency seek appropriate medical assistance immediately. Use of the forums is subject to our Terms of Use and Privacy Policy and steps will be taken to remove posts identified as being in breach of those terms.

newnav-down newnav-up