I *think* as long as your heart rate isn't dropping below 40 during sleep, it's considered normal
. You said your PVCs seem to increase when you're having a nightmare - I wonder if it is actually the nightmare that is waking up you, and not the PVC? It would make sense that if your heartrate is rather low during sleep, and a sudden release of adrenaline due to a nightmare raises your heartrate, and your heart is prone to "misfires" anyway, by the time you're awake you're having PVCs. If changing position is all it takes to stop it, and your dr. has already told you it wasn't serious, I'd just try to sleep in a position that doesn't cause it. But, if it happens frequently and starts to really interrupt your sleep you might want to get things checked out from that angle, as lack of sleep at night is almost certain to increase daytime symptoms as well. I don't know why it seems to affect you more on your right side than your left, as you said most people are opposite that. It could have something to do with the minute effect of gravity on blood flow & strain or pressure on internal organs that "irritates" your heart when you're laying on your right side I guess.