I'm a week and 1/2 out of implant of St Jude Eon Mini. I had a little bit of upper back pain last week, but today it feels like someone stuck a machete in there. I'm also having pain in my upper chest, and if I breathe too deeply I can feel pain in my esophagus. If it's not improved by tomorrow, I'm going to call the Dr. who did the surgery. I'm out of the pain med he prescribed (vicoden - which is like candy to me), so I'm only taking the oxy. prescribed by my pm. I'm not having trouble breathing - iow, my breathing is normal, it's just the pain that is bothering me.