Thanks for your reply. I am aware of the mechanics of PVCs and PACs, just not always sure what I am feeling. Last few days I have been having a lot of hard beats, and sensations in the throat and chest... more isolated, and very brief. My real dilemma was the episodic PVCs that drove me to the ER a few months ago...I was having PVCs every third beat. Now my tendency is to attribute every flutter, thump, or hard beat to PVCs... ironically, as you posted, my holter only picked up PACs. Clearly, I am dealing with a mix of both. I am quite certain that the longer episodes, where I get the high occurrence of uncomfortable beats (up to 10 - 20 a minute), is likely an episode of PVCs, where as some of the isolated events may well be PACs as you mentioned. Either way, it's safe to say - I hate them both!!!
You are doing the same mistake many of you are doing here. You think every skip or flip in the chest is a PVC. When you are stressed, especially if your heart rate is a little high, had a little too much coffee, etc, you most often have PACs.
The sensation depends on when in the heart rhythm cycle the PAC decides to "strike", what your BP is, how well your heart can contract, and more exotic causes like where in the atria the PAC origin, how long refractory/recovery time your sinus node have, etc.
Generally, you will more often feel the PAC than the PVC. In other words, PACs are more likely to produce "double" beats followed by a pause, rather than a completely skipped beat. Also, most PACs produces an "incomplete pause", so the timing between two normal beats aren't exactly two beats long. This variation can be in milliseconds, so it's hard for us to notice exactly what is a complete and what is an incomplete pause.
PACs can also cause longer pauses than two heart beats.
Also, PACs can feel as a punch in the throat/neck, followed by a hard heart beat.