Wow! You sound great! Can you cook?
Seriously, ECG suggesting RA enlargement is not necessarily a significant finding. The ECHO will tell you better. This is an ultrasound
of the heart - like when they do an ultrasound for a baby only they do it on your chest to look at your heart. They bounce sound waves off it and analyze it and make a picture - only the picture is in real time and watches the heart move!
They can see if you have fluid around the heart
They can see if any part of the heart is bigger than it usually is (smaller isn't often a problem except if your valves are tight or leaky)
Sounds like you get recurrence of your pericarditis
from time to time and it sounds like you are managing it well.
Your ECHO may well be normal, in which case breathe easy. Just take your ibuprofen
from time to time.
If your ECHO shows RA enlargement, high right sided pressures etc. (or any other significant abnormality) then your cardiologist should swing into action to identify the cause of all this and treat it.
This could lead literally anywhere (as I don't know your ECHO result) so I'm not going to venture anything more.
Good luck! I'm sure you'll be fine!