Well, for me it was a few things. When my heart issues started I had just been out on a pretty stressful job with lots of schedules to keep to in a very short amount of time.
Projects like this on my job can often push me to work over 16 hours a day multiple days in a row. I got very little sleep and was fairly stressed the whole time. Then when the job was over I got pretty shit faced drunk my last night in that town. I had to catch a ferry after just a couple hours of sleep, and then drive for hours. Well, the palpitations kicked in pretty damn good on that drive and fucked with me for about 2 weeks. I was dumb and never went to the doctor for it, but WebMD did tell me basically what I told you and I decided to to wait it out. Sleep, Diet, Stress and Alcohol consumption were all my triggers and basically the things I needed to improve before they went away. Not sure at what point the cardiac reset happened but one day they just stopped happening.
Seeing the doctor is definitely the right choice though. I mostly post this to try and take the edge of the anxiety. Anxiety about your heart is the most desperately self defeating thing at a time like that.