Thyroid and AFIB

Good Morning…. I have a recent discovery and I am interested if anyone could shed some light on the subject. 4.6 years ago I was diagnosed by my PC with hypothyroid and placed on 50 mcg livothyroxine. 3 years ago I was diagnosed with AFIB; probably had episodes earlier but can’t be sure. Recently at my request I was taken off of the livothyroxine for 6 weeks and retested by a specialist. Just received the results and Iam normal. While on the livothyroxine my FT4 was 1.55, off of the drug it’s 1.21; normal lab range is .93-1.7. I know that thyroxine is a heart stimulant, is being medicated with the drug with a normal thyroid a likely cause of my AFIB? I have been evaluated by numerous Dr.s who have found nothing physically wrong with me I.e. no known heart disease, normal BP, not diabetic; could lose a few pounds but overall good health and no family history of AFIB. I look forward to your comment’s.

Steve

Hi Steve,

A friend who is a doc & was on thyroid meds missed one and took two to make up for it. This initiated his first ever afib episode. For what it is worth.

Did your friend continue to have AFIB episodes when normal dosing was resumed?

Hyperthyroidism AND hypothyroidism can cause afib. Your lab result does not indicate hyperthyroidism. Therefore I do not believe
your thyroid medication caused the afib. You need more comprehensive testing if you are concerned. Just my opinion.

There is a good website for thyroid issues www.stopthethyroidmadness.com

Pam

Quote
SailorGuy1
Did your friend continue to have AFIB episodes when normal dosing was resumed?

No, he did not.

Hi Steve,

I had a similar story—tested mildly hypothyroid, was put on a low dose replacement and a few months later started getting frequent, really intense Afib episodes. Stopped medication and thyroid function tested normal. I’d like to say that this was the end of Afib, but it wasn’t—I just went from frequent episodes to just a few a year.