High heart rate while sleeping episode/Levothyroxine increase

[mhanan4]

I sleep with a fitbit tracker on my wrist that tracks my heart rate. Usually when I sleep, my hr stays anywhere from 49-55 bpm, occasionally jumping in my sleep to the mid 80's. I usually wake up feeling fairly refreshed.

I've been on my new dose of thyroid medication for almost 3 weeks. Going from 25 mcg to 50 mcg. Yesterday, after checking my sleeping info, I noticed a strange spike for an HOUR when I was sleeping, between 8 and 9 am, (waking up at 9:30). I take my thyroid med at 6 am everyday.

My HR jumped from the normal low 50's to almost 180 bpm, and stayed over 100 for an hour before dropping to the 50's again, I did not feel anything while I was sleeping, and wouldn't have known if I didn't wear my fitbit.

My heart rate besides this episode has been normal (not abnormally high/no palpitations) and today it stayed constant as I slept and did not spike again. I wouldn't be concerned except for the length of time it stayed elevated (an hour?!) , and the fact that yesterday after this occurred I had more frequent bowel movements/less bulky than normal. It felt like everything was flying through my system.

I am not overweight/with no history of sleep apnea or troubled breathing while sleeping. I do not know if I should attribute this to a nightmare, or be looking into calling my doctor for the concern of being hyperthyroid.

I am supposed to get my TSH tested again in March. Looking for advice as to see if I should go in sooner, or see if another episode occurs before I get worried. Thank you!

Lastly, my energy level seems to have improved greatly since being on my new dose of medication. Also  my digestion seems to be normal today, and I have not had any other symptoms (like sweating/fever/dizziness besides slight dizziness when I first started the new dose, which went away after 3 days of the new med).

[omoelo]

I have a history of Graves/Hashi going back 25 years.  Did the Tapazole for 18 months.  Treated with Armore Thyroid and currently Synthroid.   I had an emergency at Thanksgiving , chest pain, shortness of breath, high blood preasure, abnormal ekg, sweating,shivers,stomach pain,ect.  Doctor used nitro to reduce symptoms.  Diagnosed GI issue.  No heart attack .  When I returned home and saw GI he rushed me to the Cardiologist.   I passed the tests but still have issues.  
I got a Fitbit and started to monitor bpm when I felt symptoms.  Often finding resting over 100 bpm. If I walk down stairs and back  increases to 126.  

My November labs show TSH of 0.16 Free T 4 1.6 Total T3 87
I'm taking .88 mcg synthroid
I took current labs yesterday and stopped taking synthroid.  Have appointments this week with cardiologist and endo.
Is it dangerous to just stop taking meds ?  Using Ativan to reduce heart rate when needed.
Any thought would be appreciated.  

[mhanan4]

From advice given to me by my PCP and endo, you should NOT just stop the meds cold turkey, they will lower the dose and ween you off it if you're hyper.

I would consult your doctor before stopping or reducing any medication as it can be dangerous for your heart and system suddenly not having hormone in your system it's used to having.

Your medication sounds to me like it's much too high for your body if you're expressing these hyper symptoms. A TSH of 0.16 is quite low, did your doctor say anything about this in November?

[Barb135]

Just to add to goolarra's good advice, make sure when you have blood work that you have Free T3 and Free T4 tested, not only TSH, since TSH doesn't tell the whole story...

[mhanan4]

My PCP wouldn't test my free t3, and solely relied on TSH, but I will ask my endo to test all 3 and get a copy of my labs for sure. Thank you!

[goolarra]

I agree, if you are overmedicated, the symptoms would continue, not just be one time.  If you experience this again, though, talk to your doctor and have some blood work done so you know where you're at.  

[mhanan4]

Thank you!

[mhanan4]

Yes feeling so much better on this dose! I am thinking it may have been just my body adjusting as well. I will see if it happens again, I was just pretty alarmed. Thank you for the advice.

Last time my TSH got checked it was a 1.75, my endo upped my dosage because I was still very symptomatic. If my TSH has dropped too much I think I would be experiencing more hyper symptoms then just a one time episode ? I will mention it next time I go in. If it happens again though I'll definetly make an appt sooner than March.

[goolarra]

You've been on your increased dose for three weeks, so it's almost reached its potential in your blood.

Considering you're basically feeling better on your new dose, and this has only happened once, I'd probably wait to see if it happens again.  It could have been a dream that got your adrenals flowing, which kept your HR up for a while.  It could also have been a bump in the road as your body adjusts to the new dose.