FWIW - I'm completely pro vaccination.
I started having palpitations just over 4 weeks after my 2nd AZ. It started off as a very mild and very fleeting thing - 20s - I'm well aware a very very high percentage (90+ something %, 95, 99 - I don't know an exact figure) of palpitations are completely harmless so I wasn't bothered by those at all - I'm fit, good weight, etc never had any heart issues before - thought it was just age or tiredness as my sleep patterns have deteriorated over the lockdown due to disruptions to my work routines and daily life - anyway - I never even considered a link to the vaccine. Over a number of weeks the palpitations became stronger and lasted longer and I started to have moments when a sense of dread came over me and I felt unsafe standing up as I thought I was a fraction of a second from passing out so I dropped to my hands and knees for a few seconds while it passed - this was when I started to get a bit concerned but again these moments were short lived and isolated - I might have a 2-6 a day and only once a week would I have a bad moment and felt like I was going to pass out. This continued to get worse over several weeks until I was unsafe to drive for 2 weeks - once the bad patches started to last 20mins+ with me feeling like I would pass out several times a second I was able to put on a blood pressure monitor with a cuff - I knew my BP has always been fine - good in fact because I have always exercised and I know my HR is a little on the low side - resting typically 52-62 - I just thought - these palpitations are getting bad but I know they are nearly always benign - I'm not someone who panics - I don't have an anxious disposition and I don't worry about my health because - as I say - I've always exercised and been pretty healthy - however I was getting concerned - because the palpitations were lasting longer I was able to put my BP/HR monitor on and I was expecting to see low BP - I was surprised to see that my HR was being measured at low 30's - I won;t say it was falling to the low 30's as I know that the sensor can be mislead - anyway. I spoke to a cardiac nurse via the BHF and she said I should have rang for an ambulance if it had gone on for 5-10 minutes - I've never had to do this before so I was reluctant - it might have crossed my mind - I just thought I would sit it out - unpleasant as it was and hope for the best - I just thought it's only palpitations.
I did contact my GP before I had the worst weeks and I had a 10s trace and about 6-7 weeks later I had a 24hr heart monitor - but TBH it came about 1-2 weeks to late - my palpitations had started to subside - it showed 5% ectopic beats and I was getting pairs of beats together which made my BP/HR monitor see roughly half my actual HR - 30 instead of 60. Weeks went by and the palpitations completely disappeared - I feel fine - have done for 2-3 months now - not a single palpitation event. I never had any shortness of breath or chest pain at any point. About a month ago an appointment for an echocardiogram came through - I haven't had any feedback about that - I guess nothing was found otherwise they may well have been in touch I think.
So - I would feel a lot safer having the booster but I would not like ot go through all that again with the palpitations - it concerns me that the NHS with the best will in the world - may not be there for me if I really get a problem - it's possibly pericarditis or myocarditis BUT - because no investigation could be done at the time there is no way to prove anything.
gov.uk has some info on the numbers of similar adverse effects - they are low.
www.gov.uk/government/publications/covid-19-vaccination-myocarditis-and-pericarditis-information-for-healthcare-professionals/information-for-healthcare-professionals-on-myocarditis-and-pericarditis-following-covid-19-vaccination
I wondered if anyone else had been through a similar experience and either had or not had the booster. I did fill in a yellow ticket to report what happened. I am waiting for my GP to look in to what info is available to help me decide - when i spoke to him last week he said he didn't think there was any official guidance as the number of adverse similar reactions are so small.
I'm 60 and have just retired - forced in to it by the lockdown ending my self employed work - with Covid affecting meetings in person I don't currently see a time when I can ever restart so I'm saying I'm retired - not that I planned to be. I can manage though.