Is T3 liothyronine causing pounding heart?

[Greentrees1]

Hi there all

I'm really concerned I'm going to be taken off T3 as my resting heart rate is all over the place. It used to be low 60s but now its often in the 80s and even up to 100. I'm on 50mg levo and 15 liothyronine. I had trouble adjusting to t3 when i started on 10mg about 5 months ago but it settled in a ciuple of weeks. I've been in 15mg for 3 months. I take it all in the morning with water and don't eat for an hour. It's really the last few weeks I've niticed the pounding heart. I wear a fitbit so i can see how irregular it is.

I'm due another blood now as it's been 3 months.

Does anyone have any ideas?

[Greentrees1]

I should add that i was diagnosed Hashimotos summer 2016 and currently on 50mg Levo and 15mg liothyronine

TSH 0.31, FT4 16.1, FT3 4.1 before t3 was increased from 10mg to 15 mg

[cjrsquared]

Just a quick caution,, do you manually check your pulse to confirm what your Fitbit is telling you? Sadly my Fitbit is completely unreliable at recording my heart rate. It turns out that there is a great deal of variation in how reliable a Fitbit is, it is user error and also some people's physiology make it harder for the machine to record correctly.

I think the important question is how do you feel? Are you better on 15mcg than 10mcg?

[Greentrees1 in reply to cjrsquared]

Thanjs fir the reply. I've tested my fitbit in other family members and i can feel the pounding. It makes me feel odd like I can't do anything energetic.

I'm definitely better on 15mg and I've managed to get back to exercising - when my heart isn't pounding! My normal resting heart rate has always been low in the past, often in the 50s.

[bantam12 in reply to Greentrees1]

You are probably a bit overmedicated.

[Greentrees1]

Thanks. I'm getting a blood test today. Unfortunately not until 11am but it will be fasting. Thing is, I'm still not at my previous energy levels. Hopefully he'll check my folate and b12 as that's often lowish.

[Marz in reply to Greentrees1]

How is your Ferritin and Iron ? If low that can cause a problem. Vit D ??

[Greentrees1]

My ferritin is 80 and vit d 100 as I've been supplementing. I think the heat has had a big impact the last couple of weeks too.

[humanbean]

Have you tried splitting your T3 into 2 or 3 smaller doses and spreading them throughout the day? It might help. Quite a lot of people need to split dose their T3.

[Greentrees1]

Thanks. I'll try that! I thought 15mg is quite low but i guess my body might not like it in one hit.

[humanbean in reply to Greentrees1]

15mcg of T3 is a fairly low dose, but if people have been left untreated, under-treated or wrongly treated for a long time it can take a while to get used to T3.

You may find that how you dose yourself with your T3 will need to change as time goes on and you adjust to it.

[thyr01d]

Hi, isn't this increased heart rate one of the possible side effects of T3? As I understand it from my vet daughter a changing heartbeat that remains rhythmic is okay, though perhaps unpleasant, its arrhythmia that is of concern. I think Humanbean's advice sounds right, good luck.

[Greentrees1]

Thanks. I think I've needed treatment for many years. My t3 was only 4.1 on 10mg so I'm hoping its gone up a bit on 15mg. I had hoped it could be increased to give me more energy and maybe improve my sleep. My endo is happy for me to stay on 15mg but probably not increase it until my heart settles. It is rhythmic and he's happy there's no issues so that's a relief.

Hopefully my results will be in next wek and I'll know where my levels are.

How long does it take for your body to adjust to T3?i dread to think my my T3 level was before I started treatment as my T4 was very low.