sounds like me too. this will occur for several days in a row at times. diagnosed as benign, but as you know they are extremely distressing.
Has anyone else experienced?
Yes.
should this be cause for concern?
Probably not. I've had periods like that that lasted months.
If it was recent enough, take note of what your diet was the previous 24 hours and what your activities were. I discovered that there's something in a Baskin Robbins ice cream cake that will send my PVC's and PAC's into overdrive. 10-20 hours later, I'm back to normal.