I'm sorry to hear about your struggles with this and I have no personal experience with ablation or pericarditis, but as an SVT patient with an ablation scheduled for September, I have done some research and am aware of a diagnosis called "Post-pericardiotomy syndrome" that has occasionally been recognized as a "probable result of RF catheter ablation". The research refers to this complication as "rare" and I believe it is usually associated with ablations for A-Fib (where the "burns" can be quite numerous), and with procedures involving extensive RF burns (multiple accessory pathways or pathways deeper in the myocardium) and with complications of tamponade (poking through the heart wall) occurring during the procedure from catheter puncture or happening as much as a week post-procedure from weakness in the heart wall from necrotic tissue resulting from extensive RF damage to the heart muscle. In cases where this is suspected, it appears that some fairly extensive testing is done including MRI testing, echos and EKGs.
There are anecdotal cases in the literature that mention patients who "...complain of long term chest pain post ablation despite success of the procedure in ameliorating the underlying rhythm disturbances...", but the research seems unable to provide any specific reasons for this pain. Other than in occurrences of tamponade, I have not seen specific reference to pericarditis as a complication of RF ablation. However, given the delicacy of some of the heart structures and the potential power of RF energy, not to mention all the catheters and wires involved, it does certainly seem possible that pericarditis could occur, especially given that there are plenty of cases of pericarditis that seem to have no discernible cause.
It doesn't necessarily sound like your experience fits any of these scenarios, so I'm not sure if this is of any help, but if you are continuing to have pain and have not received any answers from your cardiologist you might consider going to a highly respected, high-volume ablation facility and getting a second opinion from one of their specialists. I hope you continue to heal and have fewer and fewer episodes.
Just want to correct something I said above -- there ARE references to pericarditis as a complication of RF ablation, but other than occurrences of tamponade, they tend to be unusual, however, the Cleveland Clinic (and a few other sites) do list any invasive cardiac procedure, including RF ablation, as a potential cause of pericarditis.
thanks for the info...they did have to do quite a bit off ablating for the SVT but not as much as for Afib. good luck to you