Sorry to hear about your episode. I know how frightening it can be. I haven't had the same experience you have, but I will tell you about recent experience with palpitations.
Like you, I've always experienced palpitations, but this past year they got significantly worse. Instead of being occasional, they became very frequent and even predictable when I exercised, and I also experience bouts of an accelerated rate for seemingly no reason. On top of that, my endurance when I exercised seemed affected. For a long time, I blamed the double red blood donation I did in March, but as months passed, I figured something else was going on. I made an appointment with a cardiologist, but cancelled it since my annual physical was just 3 weeks later and figured I'd talk to my PCP about it.
Long story short, my blood results from my physical showed low ferritin and high RDW. I had to Google both of those things since they were new to me, and learned I was iron deficient. Here are some symptoms of low ferritin:
Loss of energy
Loss of libido
When I started taking an iron supplement and eating a high iron diet, things started improving immediately. It's only been a week, and my palpitations are back to being occasional...nowhere close to as frequent as they'd been.
If you haven't already, you might want to get a check-up and have a full iron panel done.
Hi to both of you.
The low iron explanation is a very likely one.
It is interesting to note that low iron IS one of the causes of low thyroid function at the cellular level.
Disregard serum levels of thyroid hormone results, as they do not necessarily indicate accurately thyroid function.
Other causes of low thyroid is TISSUE magnesium deficiency, which is very prevalent in heart arrhythmia and palpitations, low cortisol, low selenium, low zinc and probably others that I can't think of , right now.
So any one of these deficiencies could be causing hypothyroid which would possibly explain ALL your symptoms including Fibromyalgia (valiantvalleygirl)! Note: Thyroid Dysfunction is VERY complex*
I'm not very regular here, however this post appeared on my screen by hitting the "wrong"button, and I decided to reply.
Please consider to look into the thyroid dysfunction and heart disease connection*. It might surprise you.
*If you need more details or links , let me know.
Love & Light