Those heart palpitations sounds like covid to me. It can cause cardio myocarditis. I suspected you hadn't been vaccinated, because you shared some of that data with questions, to which we all concluded that older people are more likely to die, regardless of their vaccination status. And they're also more likely to be vaccinated because they know they're at a higher risk. Which if you present it in a certain way, makes it look bad on the vaccines. Having said that, I've come across a lot of people who've experienced distressing problems like mine, which of course, aren't great. I think the Moderna dose is too high. Difficult though, when my husband's high risk. And I didn't want long covid either. Glad it's worked OK for you.