Hello. Welcome to HCM and thank you for your question. I understand your concern.
The situation that you were experiencing that lead you to visit a doctor, was probably mostly from an inflammatory state in the organism, such as
bronchitis. Inflammatory states in the organism tend to put the whole organism "machinery" to work, and also high
heart rate may be generated. Waking up in the middle of the night with a fast heart rate, often comes from dreams or
nightmares, some of us call it "nightmare heart rate". This is because dreams happen in a sleep phase, called the
rapid eye movement phase, which is characterized by a spike in adrenalin and noradrenalin levels in the human organism.
If there are remnants of this symptom, they could be still generated with the same mechanism as described above when it wakes you up. Also, if this is a worrisome event to you, and during day you think about it, then it generates a amount of
anxiety, which, also, is characterized by a flush of adrenalin in the bloodstream, which results in fast heart rate. If this is the case, my opinion is that there is nothing to worry about. Last, but not least, normal heart rate figures in worldwide population are 60-100 beats per minute.
I hope I was of help. Take care.
Regards,
Dr. Meriton