Hey, Maya. Glad to hear from you again, even though that's bum news about your BF.
RE: your question, it's worth keeping in mind that Constrictive Pericarditis has a clear, physiological set of signs: that is, the heart is being squeezed by the pericardium, and sometimes by calcium deposits as well, thus resulting in symptoms of heart failure (edema, ascites, jugular vein distension, etc.)
I believe you said that your boyfriend has something different though, right? Recurrent, or Chronic Pericarditis? Either way, my understanding is that the standard treatment for Constrictive Pericarditis is surgical pericardiectomy. Again, though, you've said that your BF has something different.... Regardless, I wonder if he might ask his doctor if surgery is an option. In any case, I hope you get some answers soon. (He's had the automatic, standard tests, right? I.e., chest x-ray and EKG?)
I get some of the similar symptoms still---tightness in the chest and shortness of breath---but mine is due to pleural effusion.
Also, you might want to head over to the Crohn's Disease message board. The people over there have a LOT of experience with prednisone, and I'm sure they'd be able to share their knowledge of it with you.
ps. Teri---oddly enough, my heartbeat is more obvious when I lay on my right side, exactly the opposite of what you experience. Weird, eh?