Severe hypothyroidism and atrial fibrillation — a therapeutic dilemma

Severe hypothyroidism and atrial fibrillation — a therapeutic dilemma

Posted by Michael Kleerekoper, MD, MACE  January 26, 2009 08:51 AM

A 76-year-old man with advanced Parkinson’s disease and long-standing hypothyroidism had his thyroid replacement therapy carefully monitored by his physician. A few months ago his dose was reduced from daily to just six days a week because his thyroid-stimulating hormone level was a bit low. Some weeks later he developed congestive heart failure, most likely unrelated to the change in thyroid dose because he was euthyroid when admitted to the hospital. He was discharged after a few days but readmitted within a week because of worsening symptoms of CHF. On this occasion the response was slow, and he required intubation. There was great difficulty in weaning him off the ventilator, and a tracheotomy was performed. (Hypothyroidism should always be considered in patients difficult to wean off a respirator.) He had difficulty eating, and a feeding tube was needed to maintain adequate nutrition. He subsequently developed atrial fibrillation, and amiodarone therapy was started. Improvement was slow, and he was transferred to another hospital where initial laboratory studies revealed severe hypothyroidism with free thyroxine of 0.4 and TSH, 54.

The cardiologist appropriately wanted to continue amiodarone, but what to do about his thyroid replacement? The old maxim for thyroid replacement in hypothyroid patients with heart disease is “start low and go slow." That begs the question as to whether there is time to go slow with thyroid replacement in this critically ill gentleman. After extensive and amicable discussion with the cardiologist we settled on 50 mcg T4 with both of us acknowledging that the data on which to base our decision is really quite weak.

I did a PubMed search and found an excellent review article,* but not surprisingly, it did not address the specific question in hand. In one paragraph the researchers discussed thyroid replacement in hypothyroid patients with arrhythmia and cited an article discussing dosing. I quickly went to the reference list only to discover that the citation was from a paper published in 1961. Back to PubMed, but still nothing that could really help in determining the right dose.

The next issue to address was how to give the replacement hormone. Usually in severe hypothyroidism replacement is given intravenously, but how would that affect our dosing decisions? The patient had a feeding tube, and it would be easy to give the crushed tablets through that. One problem — he was already receiving several medications through that feeding tube, and adding T4 to that mix would almost certainly impede its absorption. To ensure maximum absorption of T4 it is best taken between meals and without any other medications — yet another chore for the busy ICU nursing staff. The patient has tolerated the 50 mcg dose IV, and his overall condition has slowly improved.

PS: To my knowledge there is no concern that amiodarone will affect thyroid function in this patient whose thyroid gland has been nonfunctional for many years.

For more information:

  • *Klein I, Ojamaa K. Mechanism of disease: thyroid hormone and the cardiovascular system. N Engl J Med. 2001 ;344:501-509.

Comment by MR -- May 23, 2010 02:00 PM

Thank you Valerie for posting this!! I am just started on my journey of discovery through my whole hypothyroid mess, and was put on Levo for a few months last year and felt the worst I had ever felt in my entire life!! (47 years) Now on desicatted and doing much better, still learning though

Comment by Tom Repas DO FACP FACE CDE -- January 27, 2009 11:49 AM

This is a difficult situation. Thank you for sharing with us.

Comment by Valerie Taylor -- January 27, 2009 05:21 AM

But for the grace of the INTERNET there go I! PLEASE give this man some T3. And while we are at it, lets call a pot a pot. The doctor that reduced his thyroid medication from a TSH lab is what CAUSED his CHF. How do I know this? I was THERE 14 years ago. The culmination of 20 years on Synthroid adjusted by my TSH gave me CHF which I was dying from. Given less than 2 years to live i learned about HEART protective T3. It has taken me 14 LONG years but I no longer have CHF nor do I have High BP (was 245/148) all due to changing my OWN thyroid meds. I have since watched two more friends die of CHF from this very cause. I put myself on 3 grains of Armour thyroid and it saved my life. Heart patients NEED T3 for their hearts. Read the studies! It is all there all you have to do is apply it! And LOSE that horrid TSH lab. It does NOT work. After immediate improvements on Armour Thyroid I then took another leap of faith and started judicious use of unrefined Sea Salt. This helped lower my fluid retention and further improved my health. You see when the body is starving for sodium, it will retain all the fluid it can in an effort to not lose more of it's vital minerals. Sea salt and Armour thyroid reversed and CURED my CHF. I have since come off all BP medications and now have BP of 137/78 with pulse of 78 and am 54 years old and weigh 220 pounds. No I have never been able to lose the weight. And I struggle with the aftermath of years on T4 only that nearly killed me. I have since developed Diabetes as a result of the insulin resistance from being undertreated hypothyroid for many years. Please save this man's life with some T3 at the very least!

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