Inappropriate sinus tachycardia

I was diagnosed with IST about 5 years ago.  I tried several medications including beta blockers and calcium channel blockers with no relief.  After about a year symptoms seemed to disappear.  Now 5 years later they are back but I also found out in April that I have Hashimoto's thyroiditis.  Does anyone know the coorelation with the thyroid and heart and what other treatment options there are for IST?  My main problem is tachycarida and palpitations which feel like skipped beats.  Thanks!

[Jerry_NJ]

Sorry I don't have any direct information on thyroid and heart rhythm, but I am sure there is one.  That is, if you thyroid is not in "balance" something should be done. My wife takes a thyroid medication for something, but not for her heart.

I think too you need to find out what the palpitations are, get a Holter or longer-term monitor if necessary and get a diagnosis.

Other than beta blocker and channel blockers I do not know of anything to lower tachycardia - maybe a anti-arrhythmia drug such as Propafenone/Rhytmol, or an intrusive procedure such as ablation.