premature ventricular contraction causes

I am not a doctor but I have had a lot of personal experience with PVCs.
I don't know about the "thick heart" but the PVCs can be caused by smoking too much, caffeine intake, stress and not sleeping enough. They are generally not harmful unless they really go crazy.

I have found that if I consume a lot of calcium; milk, ice cream and so on they get worse but sometimes magnesium can stop them, magnesium can cause a lot of gas if you take too much and diarrhea. I keep bananas and cashews on hand at all times, the potassium in banana sometimes works and the cashews have magnesium, manganese, potassium and this for can work at slowing the PVCs down or eliminating them. But this is not a real fix for them just a treatment so to speak. Sometimes it's an inbalance in your electolites.

There are doctors who now can track down the site on the heart of the offending electical impulse source and using radio frequency alblation can zap the offender. I have only heard about this through a cardiologist not investigated further.

I have been through the halter monitor twice with no results. Only threw one PVC during my cardiac stress test at the very beginning and no more. The halter I don't think works at all for this, I wrote down every single one I had while wearing it and nothing ever showed up. Same thing for my mother and my sister. I tried several prescription medications, verapamil and a couple of others that did not work they only lowered my BP too much, I run low (110/62 around there) so any BP medication really lowers me for example down to 90/52 which I think is too low and I get really tired and fatigued.