Hi Luigi - yes, I had episodes of irregular beats lasting an hour or so on & off day & night for a number of years, starting in perimenopause & continuing well into post-menopause. They can be very unnerving, not to say downright frightening & at first I found it hard to believe the heart could be affected by gynae hormone disruption, but it certainly can. They do occur in menopause & there are a number of previous threads on the forum discussing palpitations that might give you some reassurance - you could use the search facility & enter something like palpitations, ectopics, or irregular heartbeats.
If you have thyroid antibodies it's really important that your GP keeps an eye on thyroid function & given the palps (especially if your heart is racing) I would personally want a TFT more frequently than annually. If you are losing weight, feel jittery, a bit manic or excessively hot, this could indicate your thyroid is becoming overactive, so I would urge you to press your GP for a TFT sooner rather than later. Please don't worry about the possible thyroid link though - even if this is the cause, it will be treatable & it could just be down to gynae hormones. Like you, when mine first began they only occurred in the days just before a period. They continued to be at their worst during this phase of the cycle, though as perimenopause progressed they happened every day - this doesn't mean this will be the case for you though.
I'm long term hypothyroid & my palps were investigated by ECG, treadmill test, echocardiogram (ultrasound) & 24 hr holter monitor & found to be harmless ectopics & this is the case for many women. They finally stopped around 3 years post-meno, shortly after starting systemic HRT (& restarting T3 - the active form of thyroid hormone). Subsequent changes in HRT regime have caused them to return, so my money's on gynae hormones as the culprit, though thyroid disease can certainly cause them & muddies the picture at menopause.
Several years after mine had started, a gynae who had previously worked in Cardiology told me many women had presented at the clinic with palpitations & after extensive investigation no abnormality could be found - but they were all of menopausal age. I hope this is a little reassuring - I wished I had known it years earlier, as they can be a source of considerable anxiety, so I do feel for you. I think it's likely your cardio investigations will be reassuring with nothing serious found, but if you feel at any point this shouldn't wait, please don't be afraid to see your GP in the meantime.
