I was on Armour for years and also had heart palpitations. Mine aren’t dangerous. I’ve had EKGs done and the palpitations come and go, but I have had periods where my heart rate was also up there even close to 120, usually when I wake up in the morning. At those times I also had hypo symptoms. I finally found that during those times my Reverse T3 was quite elevated. Perhaps check with your doctor and see if he or she will check your reverse T3. You can google Reverse T3 syndrome to see if any of your symptoms match up. But I also recommend seeing a functional medicine dr. Otherwise ordering the blood work won’t do any good since most docs don’t understand the proper ratios, etc. They will only look at the range. I work with Dr. Kenneth Woliner out of Boca Raton, FL. He does phone consults and is extremely easy to work with.