Hi Kate,
I do also get svt, or have had it the once,where I was admitted to hospital with a heart rate of 170 bpm,this only happened the once and was brought back down to normal by blowing hard into syringe and trying to blow the plunger out,odd I know but it did work,another thing they recommended was splashing my face with ice cold water.
I had no further attacks of svt but then a year later started getting the ectopic beats.I, like you do think they are hormone related as well as linking them to stress. I have just had a weeks holiday in Spain with not so much as one, I get home and within the space of 2 hrs they kick off again.I did also wonder if chocolate could be a cause as I hadn't had any all week so treated myself when I got home and it was quite soon after this that they started.I think I will give up on the chocolate for a while and see what happens. Occasionally my heart rate does get up to 90bpm for no particular reason even when
I'm resting but was told this was probably just due to being anxious.
Hope things improve for you, take care,
Jackie