Atrial Fibrillation and Hyperthyroidism

[ling]

ncbi.nlm.nih.gov/pmc/articl...

[helvella Administrator Thyroid UK]

There is a guideline which requests that you let people know why they might wish to follow a link and what they will find there. If you do not add some explanation, some people will just go straight past and not look even though they might have been interested. Others will follow and look and then wonder why they wasted their time and bandwidth.

Please add a sentence to explain. Just having a few words in the subject line is not adequate.

14. If you post a link, please at least explain briefly what people can expect to find if they follow the link. Links without such an introduction/explanation may be deleted.

healthunlocked.com/thyroidu...

[ling in reply to helvella]

Thank you for letting me know the guidelines.

My apologies, I didn't write anything as I thought the title was self-explanatory. Apologies.

[helvella Administrator Thyroid UK in reply to ling]

Trouble is, people can see that your post is about Atrial Fibrillation and Hyperthyroidism - but not where they are going if they click on the link.

I happen to recognise that as PubMed Central link and assume that it would be a link to the full online version of an academic/medical paper. But I certainly would not have known it was from 2005, nor whether you were saying you consider it wonderful or awful.

[asiatic]

Thanks for posting this. I recently posted about my Endo's concern that my TSH had dropped from 0.67 to 0.22. Looks like he was right !

[jimh111]

Sorry I don't have time to study this paper at the moment. It looks like it mixes up low TSH in the general population, in hyperthyroid patients and treated hypothyroidism. It's important to separate out levothyroxine treated hypothyroid patients. This is because hyperthyroidism is confounded by other issues such as concurrent parathyroid damage leading to abnormal calcium levels which affects bones and the heart. Hyperthyroidism usually presents with high T3 levels which is a greater AF risk than high T4.

This study academic.oup.com/jcem/artic... gives a better picture of adjusted relative risks for patients treated with levothyroxine. Figure 2 gives an easy to follow diagram. Essentially patients treated with levothryoxine with a TSH between 0.04 and 4.0 carry minimal excess risk of cardiovascular disease or osteoporotic fracture.

All the above assumes the patient's 'axis' the way their pituitary responds to fT3 and fT4, is working normally. Some patients have a pituitary that is underperforming, giving a TSH that is abnormally low for their fT3, fT4. In this case it seems reasonable to assume TSH is not helpful.

A futher consideration is that in medicine we often have to trade off risks and benefits. If the patient needs a very low TSH to have a reasonable life then we have to accept these additional risks and try to mitigate them (by e.g. exercise and beta blockers in the case of AF risk). A patient who suffers devastating fatigue is unable to excercise leading increased risk including heart disease and stroke. It's common practice across medicine to weigh up comparative risks and benefits but this is often ignored in endocrinology.

I'm a patient not a doctor.

[asiatic in reply to jimh111]

After reading both papers I am none the wiser as to where I fit in as a Graves Patient whose TSH will be under the control of Trab. On Block and Replace my TSH fluctuates between supressed/low/within range. Does this put me at risk from CVD and oesteoporosis ? I suspect this has yet to be investigated.

[jimh111 in reply to asiatic]

I think as a Graves' patient you are at an increased risk for a while. TSH will not be much use in the short term due to the effect of the TRAb antibodies and follow on effects. I believe they should monitor your fT3, fT4 rather than TSH.

You might also like to see this post healthunlocked.com/thyroidu....

[asiatic]

I have updated my profile to give more info on my situation. You will see I am on block and replace. Is this something your doc has considered ? I am feeling well on it and it keeps me euthyroid.