Hi Hopeful,
I have had bouts of palpatations throughout peri-menopause both before and during HRT. It was really bad pre-christmas for a couple of months along with anxiety. I was on 4 pumps of Oestrogel and 14 days of 100mg Utrogestan. My research indicated it could be due to too much or too little oestrogen so I plumped for one and dropped to 3 pumps. Not sure if it was pure co-incidence but palpatations (& anxiety) disappeared. Have had a re-occurance of anxiety/jitters this past couple of weeks (for no apparent reason) but palpatations have been nowhere near like they were like last time (so far - fingers crossed).
My personal opinion (caveat I am not a medic!) is that there are several factors at play and it is trying to getting the balance right with both oestrogen and progesterone supplements against your own levels. I think when your own body makes a step change (which mine seems to do every few months

) it throws out the HRT regime so its all a bit of trial and error trying to tweak the balance between the 2 hormones. Maybe try 50 patch?
Hopefully someone else will comment with more helpful and informed advice.
I wish you well x