I have actually experienced two different types of "fluttering" in my chest.
 One was with extremely hypo symptoms.  I had terrible chest pains (turns out
it was pleurisy and inflammation as a result of my Hashimoto's), skipped
heart beats, and a strange fluttering sensation in my chest.  When I was
first put on medication, I began to have heart palpitations, which were
absolutely exaggerated by my chest inflammation.  The sound echoed through my
chest, ears, and entire body.  At the time, I thought I might be
overmedicated, so they worked me up slowly to the .075 (my doctor at the time
reminded me that they normally only had to do this for old people - I was
only 33!).  I later began to see the pattern, that my heart palpitated as an
adjustment to each time my dose was increased.  I am now on .125 and have
been through a number of dose changes (9 to be exact!)

My aunt, from whom I inherited Hashimoto's, had a heart attack 25 years ago.
 Believe me, I've been very careful about my heart.  Any time you have heart
palpitations or chest pain of any type, it should be taken seriously.  Call
your doctor to make absolutely certain that what you're experiencing is
normal.  After talking to him/her, you may wish to also monitor your own
heart rate and blood pressure.  You are the best person to monitor your own
symptom changes because you are living in your body every day!

Just some thoughts, but it sounds like you're already listening to your body.


God bless!

Cherise