Did you read the conclusion?
Quote
This study revealed a noticeable prevalence but relatively benign prognosis of new-onset VAs post RFCA for AF. Increased serum leukocyte counts ≥50% post ablation appeared to be associated with new-onset VAs, implying that inflammatory response caused by the ablation may be the underlying mechanism.
In other words, the PVCs are a reaction to inflammation and therefore should diminish over time. They aren't due to anything done to your ventricles because nothing was done to your ventricles. No catheter ever touched them.