I recently had major recent sternum pain, no reflux issues, and fluttering.  I had a stress test done last Fall and everything was okay, so I'm thinking it is AS.  I have had lower back pain for years (at least 16 years) and more recently have it in my middle back too.

I get sternum pain (breast bone) pain and it puts stress as if its stressing my heart but I don't think its my heart, I'm going to have test done for the heart.   I hate this I really hate this, it feels like my whole darn body is going to pot.  If it isn't one thing its another.

I was admitted to the emergency room about 2 months ago with heart pulpatations and chest pain that went through to the back. I thawt I was having a heart attack at the age of 26yrs instead after hours of tests and poking and prodding they found that the chest bone that protects the heart was inflamed from our infamous friend we call AS :-( docs said if I take panadein forte for the pain and nurofen for the inflammation then it would go away after a few days. 2 months on and I still get tightness, pain through to my back and pulpatations. Seen my rheumatologist a week ago and he said it was AS related also and that's it's now affecting my chest bone/ rib cage/ lower back/ hips etc oh the joys!

Middle and lower back pain are the norm for AS. Heart palpitations are likely the result of anti-inflammatories. Nothing unusual here. (These are not the droids you are looking for.)

I don't think I've had palpitations, but definitely had the pain in the middle of my back.  I thought it was heart burn/acid reflux for years.  Nexium (for reflux) helps with the indigestion but doesn't help with the back pain.  X-rays show arthritis there though, so it's more likely related to that. A friend of mine (also has an auto-immune disease) gets heart palpitations.  She's been to cardiologists and had ekg's and all sorts of tests.  Even an ultrasound of her heart, all showed nothing.  Good luck!!