I to had been experiencing heart arythmia. Something felt off two weeks off after my first vaccine in March second in April followed by very bad aryythmia with a halter monitor. I thought it was my Hoshimotos which became hyperactive. It gradually went away wants by blood work started coming back to almost normal for thyroid. This changed 3 times since middle of April. Upset with Endocrinologist that my thyroid reacts to stress. Meanwhile she’s calling for blood in three weeks. Dah. Upset.