Euthyroid Hashimoto's symptoms?

[Fran71]

Dear Doctor,
I

[eik]

A related discussion, Prophylactic treatment of Hashimoto's thyroiditis. was started.

[lazydog]

Heart palps started whilst i was pregnant with 1st baby.  They have continued after hypothyroid dx and medication.  
If you have thyroid antibodies you cannot rely on TSH reading as it is common to have hypo symptoms at a very low TSH.  You should be treated accoridng to symptoms and I would think most people are medicated.

[Fran71]

I've checked my last blood test from December 05. My TSH is 1.72, range given 0.400-4.00. Still my cardio thinks the thyroid may cause some imbalance and heart over-sensitivity to catecolamines, since I have thyroiditis despite normal blood results.
I hope it makes sense and it is true...otherwise it's hard to explain my tachycardia and PVCs.

Fran

[Fran71]

Hi and thanks for your post. Sorry for the delay, I just saw it.
I'm not sure which TSH range my lab uses, I'll check into it. I just saw a cardiologist who specializes in arrhythmias yesterday. He confirmed my heart is perfect and suspects my thyroid may play a role in my palpitations, although I'm still euthyroid. Is your thyroid function normal, or anyway was it normal when you had palps? Are you on any medications to control your palps? I'm taking a betablocker, but I know this only keeps the heart calmer but does not act on the real cause...if there is any, other than oversensitivity to catecolamines. Echocardiography done 2 years ago showed no mitral valve prolaps, but I'm scheduled for another echo next month just to be sure everything's still OK.

Thanks so much again and have a nice day

Fran

[lazydog]

Dear Doctor,
I

[Mark Lupo, M.D.]

Hashimoto's does not first imply hyperthyroidism.  While some patients with positive antibodies may develop hyperthyroidism (either called Graves or Hashitoxicosis) this is not the norm.  Positive antibodies are most often associated with a destruction of thyroid tissue and loss of thyroid function.  The quoted rate of progression to definitive (not borderline) hypothyroidism is about 5%/year.

The palpitations are not common in hashimoto's but is possible - however I would have expected abnormal thyroid function tests typically.  I have seen a few patients with borderline hypo from hashimotos who experience palpitations with anxiety and starting a low dose of thyroid hormone did help (or was a placebo effect...).  The tachycardia can sometimes worsen in patients with essentially normal thyroid function tests who start thyroid hormone treatment, so generally there is hesitation to do this.  However for a young, otherwise healthy female with a structurally normal heart as you describe, a trial of thyroid hormone at a low dose could be tried and stopped if the situation worsens.

Prophylactic treatment of an otherwise asymtpomatic euthyroid patient with Hashimoto's is not indicated.