SVT and Hashimoto's

[newmom39]

I have recently been diagnosed with SVT after a halter monitor as a result of a hospitalization for a very high heart rate.  It coincided with my increased dose of thyroxine after a number of years but it was only increased a very small amount.. however,  the dose must have been too high so I changed it back to the lower dose and my TSH is in the normal range on all tests?  Could the change in dose have triggered the SVT?  Will it go away once my TSH has been normal for a while?  Have you heard of this before?  I also have peaked T waves too during my episodes of palpatations?  Is all this normal with Hashimoto's?  I am scheduled to see an Electrophysiologist?  I have not taken any meds and have a normal sinus rhythm?

[goolarra]

I have both Hashi's and SVT (Wolff-Parkinson-White syndrome).

When I was started on too high a dose, when I tried to increse too rapidly and when I was overmedicated, my very first symptom was always increased number, intensity and duration of SVT.  

Just to give you a perspective, newmom39, I increased from 75 to 81.5 mcg, which was enough to make me overmedicated and get my SVT going wild.  How long has it been since you decreased?  Did you discontinue at all for a few days before decreasing?  Do you have actual FT3, FT4 and TSH results and reference ranges (these vary lab to lab so have to be posted along with results)?  TSH does not cause any symptoms...it's your FT3 and FT4 levels that can cause SVT.  I don't know about the peaked T-waves.  I saw an electrophysiologist for my SVT.  He put me on a beta blocker, which controls the SVT very nicely.

Jamierb, by and large, any thyroid meds with T3 in them (which includes Armour) are contraindicated for patients with heart arrhythmias.  You might want your doctor to re-evaluate meds in light of the recent SVT diagnosis.  T3 has a very direct effect on the heart.  Thyroid meds can exacerbate a known arrhythmia and bring to the forefront previously unknown conditions (like it seems to have done with both of you).  Beta blockers (atenolol, in my case) were a lifesaver.  Please post your labs and ranges as well.

Are either of you aware of the Valsalva maneuver?  You can google it and get a description.  It's a technigue for stopping SVT or other tachycardias and might be something to ask your doctor about.  It was suggested to me by my EPs, and it really does work.

[jamierb]

I wanted to see if you got any more information on this.  I too was just diagnosed with SVT (yesterday to be exact) and have been dealing with hashimotos hypothyroid since last november.  I had been on Synthroid, but was having awful reactions from it (burning heart, chest pain, swollen all over, weak muscles) and so started taking 45 mcg of Armour at the end of this June.  Its been 3+ months and my TSH, T4 and T3 are all in normal ranges with the Armour but last week I started getting the heart palpitations on and off in sedentary positions.  After wearing a monitor for 7 straight days, I was told it was SVT but didn't have anything to do with the Armour.  I don't know what to do, because I don't want to go on any more medication, but when I get the flare ups of SVT at night I can't sleep at all.  Have you found out any solutions for this?

[KD9ER]

Bump for a better answer....