Inappropriate Sinus Tachycardia

[flipflopgirl]

I've recently been diagnosed with IST, after months of tests, meds etc. I also have very frequent runs of bigeminy and short runs of NSVT (5-6 beats at a time. I have a few questions I'd like to hear your opinion about...as I wait to see my own doctor
1. What is the likelihood of developing cardimyopathy from IST? If I don't take medications I can have rates up to 150-170 for hours at a time, despite making all the usual lifestyles changes (no caffeine etc.)
2. Is ablation an option to treat IST? If so is it usually successful?How risky?
3. Is the IST and the ventricular ectopy related. Since I have a normal heart by echo, I wondering if the IST somehow causes the venticles to be irritable as well.
If it's of any consequence I'm 29, female...exercise regularly,relatively stress free good cholesterol, mild HTN, don't and never have drank or smoked...and sadly now , no coffee either :(
I'd appreciate any answers you can give and thanks for providing this great service.

[prjose56]

Does anyone experience a variability in their heart rate?  I bought a heart rate monitor and constantly monitor my heart rate.  Just moving around can cause it to jump 20-30bpm...sometimes even 40bpm.  The rates aren't really sustained that long though.  I can't explain this.  Docs say it's anxiety, but I'm on vacation and don't really feel anxious.  Can anyone help?

[flipflopgirl]

Hi..it's normal, in fact healthy for your heart rate to vary from beat to beat. Most healthy and or young/fit people have a large degree of variability in their heart rate, anxious or not.

[jasta]

This is my first time using this resource and thank you all for sharing your experiences with your arrhythmias.  I'm a 35yo female with arrhythmia dxed since age 21.  Have been on beta blocker since then.  I am now on 2 beta blockers, calcium channel blocker, and my resting rate is staying 130-160bpm.  My bp is staying around 80/60 because of the above meds.  Have an appointment with electrocardiologist in 2wks to discuss ablation.  My question to you guys is do you experience chest/back pain with your arrythmias?  I have non stop for about 2 days and don't know if it's anything to be concerned about.  Thanks!!!  jasta

[tickertock]

To be honest I never was really diagnosed with IST, just a high resting heartrate, usually in 90-110 bpm at times 115-120, but probably averaged out to high normal in a 24 hour period. I had this all my life , it never did just start with me and my heart responds fairly normal to exercise maybe just a little higher than the average,but I always wondered about IST. I also notice that many persons with a high or low resting(either end of the extreme) heartrates often go on to develop PVCs or even occasional small runs of NSVT such as was the case with me, though every test indicate an essentially normal heart.

I have always been a high strung person with anxiety issues so I guess that is a contributing factor in my case also, I know for the last 20+ years beta blockers have been a great relief to me.

From what I gather IST can be difficult to treat and ablation usually never works for long and those that ablation works one is usually dependent on a pacemaker.

I also understand it usually gets better in middle to old age for some reason, rarely causes cardiomyopathy , but can in rare cases. I am not doctor this only my undetsanding of IST. Good luck, hope you feel better soon.

[KAD]

I had IST for about one and a half years.  My rates were very rapid all the time with rare episodes less than 130.  My doctors told me I would for sure develop cardiomyopathy and I took them very seriously(I'm only 28yo)  So I underwent an ablation to the SA node.  The first ablation did not do anything and the IST returned in about 1 week.  The second ablation did to much and they ended up ablating a little to much of the sinus node and I ended up needing a single chamber atril pacemaker for my heart rate dropping to 30-40 beats per minute.  About 3 months after getting the pacemaker the IST came back again, with heart rates in the 130's.  So they did a third ablation, this one seemed to have worked(knock on wood).  It was done this past April and now I am dependent on my pacemaker for my heart rhythm, but it's better than getting cardiomyopathy.  I was told that ablations only have about a 50%-60% success rate, but I don't really know what the alternative would be for severe cases of IST.  The meds made me feel awful and were ineffective anyway and I didn't want to just wait around for cardiomyopathy to develop.  It's a really tough decision with this problem.  It's kind of a no win situation.  I hope thing do work out with you and hopefully you have a good cardiologist.  I am very fit and active just like you and the pacemaker did give me the lifestyle that I wanted back!  Happy New Year!

[flipflopgirl]

Tickertock...did your IST start after any identifiable (sp.) event? I had never had any problems until I started exercising! About 3 yrs ago I lost around 60lbs through diet and somewhat vigorous exercise and thats when everything went downhill. I find it bizarre that people with young and healthy hearts can all of a sudden find themselves with these rhythm problems. I also notice on this site that many people have been told it is "anxiety" causing their problems. I shake my head at this. Iknow how aggravating this whole IST mess is to me. While I'm sure anxiety contributes to any health problem, I'd like to know how anxiety explains one's heart racing to 170 simply from washing one's hair in the shower!

Happy New Year to everyone and best wishes for a healthy or healthier 2006.