Meds are helpful as mentioned and usually pretty well-tolerated unless you have AV block or hypotension.Depending on frequency, length of the episodes and preference cardiologists generally use either chronic preventive therapy with a beta-blocker or calcium channel blocker, or pill-in-the-pocket with flecainide or beta-blocker. If you have a favorite vagal maneuver those can sometimes work too.These are very rarely life-threatening. Ablation is effective but can't help you negotiate the NHS system. Fixing the iron deficiency will also help. Our hematologists do have some patients with chronic iron deficiency anemia who can't catch up with oral supplements who have scheduled IV infusions, but only after every possible source of ongoing blood loss or iron malabsoprtion is addressed (celiac, heavy menses etc).
I have also been having infrequent runs of (possibly) SVT, which also seem to be hormone related, although Sods Law they have never appeared when hooked up to hospital machines, only a 6 lead home device.I also have a resting HR of 50-60 but have found beta blockers insanely useful. I take a super low dose of bisoprolol and it seems to be just enough to stop my heart going into these fast rhythms but not so much that my heart feels too slow. I was sceptical at first too, but Im glad I gave it a go. I drink a tin of coke each day and take stimulant medication and I will only get a brief run of SVT once in a blue moon. Whenever Ive stopped the beta blocker the issue has come back so it must be doing something.I hope you manage to get to the bottom of things and find a solution!