I had this same thing happen a few times before but not long enough for it to be caught, but I know that my heartrate and pulse was regular and not abnormally fast during the episodes, I posted about this quite sometime ago, maybe if you go back in the archives you might find it. I know its quite scary when it happens.Hope you get some answers and feel better soon.
Tell your doctor. They would need to see and examine you to try to figure out what is causing that. If it is constant, an EKG would show whether you are in normal rhythm or not. I cannot tell you what it is causing the buzzing without seeing you --- it is possible that there is not a good answer.
I have been having the same problem. I thought it might be atrial flutter (not a-fib) because someone once told me that you can have atrial flutter and have a pulse that remains normal. My pulse stays normal but I hate this buzzing.
I did go to the doctor. I felt so stupid. I told him it was kind of like if you were pushing a grocery card over really rough concrete. That vibration you feel during and right afterwords is kind of how it feels. (but just in my chest area) He ran a ekg and took blood. He said sometimes infections can make you feel that. But of course I didn't have anything wrong with my blood and my ekg was normal. Have you had a complete work up for your heart? If so, it probably is benign. I am perimenopausal and I have read that you can get this feeling during menopause too.
It is good to know that I'm not the ony one out there. I still think it might be a flutter but when I mentioned it to my doctor he looked at me like I was crazy.
A related discussion,
My heart is buzzing was started.
I will go to my doctor. And thank you for responding so quickly! Have a blessed evening!