Flare up???? Or just pain????

Tossed and turned all night, woke up with a dull pain in my shoulder that has now spread to both arms and shoulders. I am going to try some heat therapy for today and get my butt to the YMCA for some swimming in the morning. I have to work in a few hours and that is the last thing I feel like doing. On a side note, can anyone tell me about heart palpatations and RA. I noticed they are increasing and I wonder is this from the meds or just an RA side effect????