It obviously goes with saying that doctors should be visited, etc; also, there are different types of arrhythmia and palpitations, but.......

apart from the better-known causes and treatments, here is some lesser known info about arrhythmia:

Abdominal/diaphragm pressure, from eating huge meals, having reflux, being overweight, or just bending over and straining etc, can trigger arrhythmia through irritation of the vagus nerve.
Here's a long discussion about it, which includes some very interesting anecdotes:
http://forum.asktheneurologist.com/p...erve-t396.html
You'll find heaps more if you Google "arrhythmia vagus nerve gerd"

Also, check out: http://en.wikipedia.org/wiki/Roemheld_syndrome

Other people have stopped or improved their arrhythmia through supplementation and/or avoiding triggers. Supplements that are often touted as being beneficial include magnesium, iodine, iodine taurate, taurine, amino acids, potassium (low amounts) or by simply eating more protein (etc). Common alleged triggers include msg (both 621 and 635), aspartame, cinnamon, ginger, sulfite additives (the "200s"), natural glutamates, caffeine (of course), even gluten, etc, etc,

There are lots of interesting anecdotes about triggers and iodine on here, in the comments section under the less-than-complete initial blog entry at the top of the page, which I recommend skipping.
http://www.livingwithatrialfibrillat...ersonal-story/

Acetaldahyde, a byproduct of breaking down alcohol, and candida, can also trigger arrhythmias.
Google it; there's lots out there.

Anxiety/stress is said to be a cause. Mild anxiety could be a protein deficiency, due to low serotonin, via low levels of certain amino acids.
http://anxietyforum.net/forum/showth...red-my-Anxiety

Here's an interesting forum post about low serotonin, Roemheld and arrhythmia:
"In absence of heart disease, Roemheld's is typically caused by low GABA levels, low norepinephrine levels and/or low serotonin, and occasionally low acetylcholine. Levels of these neurotransmitters can be addressed with medication or by using natural means. This is why Amitriptyline (prescription) works, it elevates serotonin and norepinephrine activity."

Hmm, what else? Hypoglycemia?

dehydration, drugs, sleep apnea, lack of sleep......

http://stanfordhospital.org/cardiova.../external.html