I have the same problem. My issues have gone back 5 years. From not being able to sleep to cardiac episodes. I recently figured out (by accident or coincidence) that it is food. Specifically gas and bloating. Basically, you are bloated so much that it pushes the diaphragm up higher into the chest and irritates the vagus nerve, then you get the palpitations. The nerve triggers the heart rate to slow down, then the brain goes "whoa, wait a minute!" and then tries to increase the heart rate. You get that pause/thump! To "test" the theory you can just fast for around 18 hours and then eat. Just for fun, make sure there is dairy in the food you eat next. Now set a timer and see how long it takes to feel those PVCs. I may be completely wrong but... my issue is this. Roemheld Syndrome. Google the symptoms.