You might want to get a referral to a cardiologist to check for mitral valve prolapse. I didnt get mine diagnosed until I was in my mid 20s. You might want to google it and see if you have other signs of it (like nearsightedness, irritable bowel, scoliosis, etc.).http://www.mitralvalveprolapse.com/symptoms.html
Mitral valve is a weird thing. Cardiologists will tell you its no big deal and not life threatening, but for those of us who've had a sleepless night or two, its hard not to feel freaked out. When I did research and found out that mitral valve is just a part of a larger nervous system imbalance, A LOT of things made sense. And when I essentially cured mine with a magnesium supplement, I was truly grateful.
I stopped taking the Cal-Mag because it wasn't bugging me, but now its back with a vengeance this pregnancy (which is odd because the rumor is that its supposed to get BETTER during pregnancy. argh).
Again, I can't say whether the Calcium-Magnesium helps all palpitations or just Mitral Valve related ones, but I guess I suggest to anyone experiencing palpitations to get it checked by a cardiologist just to be sure. I had doctors telling me it was stress, and at one point felt like a fool about the whole thing. Its validating and reassuring to find out the cause and be able to take steps toward health. I would have panic like attacks randomly and one doc wanted to give me Prozac! The trigger was not anything emotional. It was because I had one too many beers or a too much coffee, etc. So frustrating for people to think its all in your head.
Also, I don't consider myself unhealthy by any means, but I have a list of small health issues I've experienced. It was bizarre to read down the list of symptoms and find them ALL on the list (i.e. nearsightedness, slight scoliosis, irritable bowel, migraines, etc.)
Anyhow, best wishes to you all. Hopefully that website will be of some help to someone.