Yesterday something scary happened. I was on my computer in the evening, when suddenly my heart went crazy for a few seconds. It wasn't pounding, but I could feel it beating through my chest, and it was totally irregular. After about 5 seconds, it fixed itself, and now my pulse is back to about 68 BPM in regular fashion. I've had blood pressure, oxygen levels, ECG and blood tests done which were all fine (except for the possibility of hyperthyroid), but after this I'm hoping to get a Holter and an echo just in case.
My question: can this type of palpitation be caused by anxiety or hyperthyroidism? Also, is this what people call "fluttering in the chest"?
This just scared me, as I've never had this type of palpitation before, so I want to know whether it could indicate something serious. I was worrying a bit that day, but not at the time it happened. I was scared to go to bed last night after it happened.