I just spent 6 days in the hospital and the final diagnosis is Dressler's syndrome. I know this is a delayed form of pericarditis but, how long does it last? I've been taking ibuprophene 4 times a day for the past 6 days and it does not seem to be getting any better. The day before this struck I was walking 3+ miles a day, riding my bike and looking forward to going back to work in the next couple of days. Since this hit, I get really tired every afternoon and end up taking 2 hour naps to recover. It's getting frustrating since this has worn me down worse than the surgery.