Heart problems
On day 9 post-op, I developed atrial fib and landed in ER twice in 12 hrs. The first episode they were able to convert me to normal rhythm with one dose of IV lopressor. The second one required more IV meds. After that, I had to start seeing a cardiologist on a regular basis (oh joy LOL).
I haven't had any episodes in over 6 months -- meds have been reduced. They never determined an exact cause for the A Fib -- but most likely the stress of surgery (and the fact that my potassium had taken a serious nose-dive in the week I'd been out of the hospital)