Happens to me all the time.
Kind of feels like a little bit of shock.
Coughing activates the vagal nerve, which can reset the beat (so I've been told).
The more you train yourself to take it in stride the less impact it will have.
Good luck.
i to have pac/pvc and i have many things , bit not the dizzy thank goodness the light headed yes and it does come with these extra beats sometimes