I've had a pain in the sternum (breastbone) several times over the last few months. It appears to be benign - evidenced by the fact that I'm still alive - and I assume it's part of the RA attack on connective tissues. Apparently 30% of people presenting at A&E with chest pain are diagnosed with it and I can see why people panic - it first struck me a two in the morning which is not the time of day you want to be afflicted by a sharp pain in the chest! After a moment or two of rational thought I decided that my breathing was normal and I probably wasn't dying. Also, the pain got worse if I pressed my breastbone - I don't think that happens with heart attacks. My heart rate was higher than normal but a sharp pain in the chest in the early hours of the morning will have that effect. Sometimes it radiates through to my back causing a pain where my wing muscles would be if I had wings. Anyway, today I found out this symptom/condition has a name. It's costochondritis.