Some good advice form donna80
I'd add, why were you up at 1 AM? Is that normal for you? If not a normal time to be awake and for how long, that in itself could have put extra stress on you psychological and physical systems... and made the heart rhythm misbehave.
It is good to get it checked by a doctor, but I'd say try to take your mind off of the problem and focus on Christmas and family and friends.... and see if that makes you feel better. At least it will help you get to the time of your doctor appointment.
Awe bless you, i can imagine how frightened it must be..
Did you take your pulse by any chance? I spect it was part of a panick attack, that has happened to me before, sitting there minding my own business all relaxed, my heart rate is really slow like in the 60's (normal for me is 70-80), then it speeds up to over 100bpm, then i freak out!
I am sure there is nothing wrong there, or you would of possibly had more symptoms, please don't stress over it, i know its hard (i am going through heart anxiety right now, don't see cardio till 5th jan).. and what scares me the most is feeling trapped with this british weather, which we are not prepared for!!
Ask yourself these questions, Do you think you smoked to much? What did you eat? What were you thinking?.. These can all be a trigger!!
I for one have been keeping a food diary since my horrible nasty episode on Tuesday!!
Big hugs