Hypothyroidism, high TSH and Afib

[DeltaDawn23]

I had 2 episodes of Afib in December 2012 after nearly 2 years without an episode.  I am hypothyroid and when I was told my TSH was high, indicating my thyroid needed supplement, I resisted because it always seems that more Synthroid equals more arrythmias.  Now my synthroid has been increased slightly (from .88 to 100) and my TSH has gone from 4.63 (high) to .52 (normal range).  I just read that a high TSH can make you more susceptible to afib.  Anyway, I'm doing fine on the higher dose supplement and wonder if some of my troubles could have been caused by not enough supplement.  Any comments?

[MichelleP_3811]

I would think you are accurate.  When I went into my regular doctors office after my ablation a couple of months later my heart rate was elevated more than it should so she tested my tsh.  It actually came more on the low side but within range but because of it I researched thyroid disorders and did find that they do contribute to heart rhythm issues.  Not sure if they cause afib but I would think if they affect the heart they can affect any issue with the heart.  The going consensus seems to be that the faster beat occurs more in the arena of hyperthyroidism as shown in people with low tsh levels so when they medicate you to bring you down it might be making you slightly hyper.  I read as well it can be very difficult to find a balance and maintain it with thyroid problems.  I would say if going too low you notice more afib then insist with the doctors that your meds be adjusted so you aren't so low.   That said you said you read that being high can lead to afib.  That makes me think that being on either end is not good for the heart so this would tell me to be very diligent about your levels and maintaining a good range.  It would be awesome if this is your trigger and one you can maintain to keep the afib away.  Fingers crossed.

[DeltaDawn23]

Thanks for the finger crossing!  I read this in a newspaper article and when I think about it, I believe I've read it before (high TSH can = afib).  Actually, as you said, at either extreme it can cause trouble.  My EP had no explanation as to why I would suddenly go into afib, other than "that's the way afib is."  Wondering why when they notified me of my elevated TSH they didn't suggest it might have factored into my 2 back to back episodes.  Anyway, I am hoping having it normalized will make a difference.  Thanks for the input.