I suffered PVC's on and off for 20 years (I'm 59). After wearing a Holter monitor and various tests my doc (former NASA flight surgeon) suggested that I excersize harder (I walked a lot) but limit my bursts to no more than 18 seconds at max hr (about 170) and not push it beyond. So I cycle an hour everyday to alternate days and push myself constantly but not balls out, like say at 85%. After 4 years I've exercised myself right out of the PVC's. Diet played a huge roll as the PVC's always happened in the eve about 2 hours after eating and it was eventually discovered that I also have GERD. Given my history of an extremely high and nearly life threatening fever at age 3, I had been told that I likely suffered some nervous system/heart damage that led to a slight but chronic heart murmur that I had until my early 30's. I also got the GERD under control with the diet change & constant exercise & inclined sleeping (what a pita). Evidentally I've got something going on with the vagus nerve and as long as I stay with the diet, exercise, keep GERD at bay, I've been better than fine. I sleep pretty soundly but my wife admits to checking on me now and then just to make sure I'm in this world.