I had this as a side effect of covid last year. You are correct, no medication was given and they won't actually do a biopsy of your heart due to the risk so t

I had this as a side effect of covid last year. You are correct, no medication was given and they won't actually do a biopsy of your heart due to the risk so the will simply wait and see. It feels like a big deal. I had never had heart issues and it felt like my whole system was unstable. Hard to describe really. I don't know how serious it is, however. The cardiologists just tested my heart, saw that there was no blockage and the blood flow was strong and told me to rest. edit to add: On the second dose of Pfizer, I felt a minor version of this for about an hour in the middle of the night after a morning shot. No other symptoms beyond a strong immune response.