Hope your husband will get good care for his a-fib and the cardio can get to the bottom of it. Good to submit a VAERS. But does his situation have anything to do with ET and the dangers covid poses for blood cancer patients? My husband (no ET) had a heart attack and emergency stent installation after a covid vax. Docs said all that plaque took years to build up long before he got the vax. Sometimes things are a coincidence.