HEART ARRYTHMIA due to thyroid. HIGH TSH.

Hello.
Thank you for your query at DoctorSpring.com
I understand your concern.
You have a subclinical hypothyroidism (raised TSH with normal T4 and T3) which is a milder form of hypothyroidism. Your requirement of thyroxine is low and hence difficult to titrate with the stregnths of 50 or 75mcg. I suggest you reassess your thyroid functions after being off meds for atleast 6 weeks.
Then start at the lowest possible dose of 12.5mcg and retests only after 6-8weeks to adjust the dosage, not earlier.
adjust the dose by increasing by 12.5-25mcg and keeping a target TSH of upper half of the normal range.
Your symptoms, other than arrythmia may also be related to menopausal symptoms after stopping estrogen. consult a gynecologist for that.
Feel free to discuss further,
Regards.

Thanks for the reply. I am not surprised you suspect mild hypothyroidism. However, I would like to introduce another hypothesis for your consideration. Can intermittent T4 therapy, or overdose of thyroid meds, generate this same pattern of thyroid function tests? I am referring to the pattern of high TSH with normal T3 and T4 values? In other words, could stopping and starting my meds various times over the last two months have caused high TSH with normal T3 and T4 values? What values in the test are you basing your diagnosis on, the TSH? The free T3 and T4? Or both together? Would the T3 and T4 values be considered normal if it weren't for the elevated TSH? Please refer to the October 13, 2013 thyroid test I just uploaded with this message. Please note that at the time of the test, I felt very stable. Please also notice that the free T3 and free T4 were both at the lower end of normal, not toward the middle as they are now. Is it possible that in my case, I feel best when the T3 and T4 are at lower ranges? That when these values rise, or get further from away from the bottom of the range, I become symptomatic? Now, if you refer to the most recent test taken in August, both T3 and T4 are at the middle of their ranges and I begin to exhibit symptoms. Therefore, is it possible that the arrhythmias (and other earlier symptoms I experienced before the arrhythmias started) are a result of having higher T3 and T4 values? Isn't it possible that irrespective of the labs, the serum levels reflected on the recent (August) labs are too high for me to function without symptoms? Is it also possible that the sudden instability in the dose I was stable on was instigated by the cessation of estrogen? I have read that thyroid function is affected by HRT. I also may have neglected to mention that while I had stopped taking the estrogen for several months, I continued to take 15 to 20 milligrams of progesterone. Perhaps I was progesterone dominant? And would this affect thyroid function? Are there any other scenarios that could have contributed to my sudden hyper-like state or instablility on the dose of levothyroxine and T3 I had been taking with success for over 10 months? Should I resume taking estrogen until the excess T4 and T3 are washed out?
How long will it take for the arrhythmia to stop? It is the only symptom that is left, but seems to be the most robust. Any other recommendations or opinions would be greatly appreciated. Test from October 2013 when I was very stable and felt great:

Hello.
Thank you for the follow up.
TSH will remain high even after T3 and T4 become normal after starting thyroxine. TSH will take 6-8weeks to normalize after change of dosage. Dose of thyroxine needs to be titrated against TSH as it is a sensitive marker of adequacy of thyroxine dosage and thyroid hormone levels. Arrythmia will disappear once the thyroid hormone levels normalise, and remain stable. Till then you can use Metoprolol or better still, Propranolol to reduce the heart rate and also T4 conversion to T3.
Regards.

Doctor, Thanks so much for the thoughtful reply. This service has been really helpful.
Sincerely,
Christine Folgmann

Hello.
Thank you for your appreciation.
Do get back to me for any additional queries.
Regards.

Hello again Doctor,
I have switched over to propanolol extended release- 60 mg per day. The heart rate has slowed to 60 beats per minute and the blood pressure stays down too. But I still feel the PVCs several times a day in runs that last for about an hour or two. I am now 35 days without any thyroid meds. I will retest my levels in another 2-3 weeks, and then titrate with 12.5 mcgs as you said.

At what point can I expect the PVCs to stop?

When my TSH is low?

Or will things settle down in a few weeks when my body has adjusted to having zero thyroid meds?

I had no problems with my heart prior to being diagnosed hypothroid so it seems logical that I will simply revert to how I was before I started taking thyroid meds. Thanks so much, Christine Folgmann

The VPCs are likely to settle down once the thyroid function status stabilizes.
Continue the Propranolol till then.
If it persists thereafter too, then other causes will have to be explored.
Also avoid excess of coffee, tea and smoking, if you do.
Regards.