Welcome to KA Roni, glad you found us.
Yes, SI and rib pains are common for AS sufferers. In the majority of cases, our bloodwork show as normal. Also, in the early years of the affection, X-Rays will not show any problems, making AS quite difficult to diagnose early on.
Have you ever had any X-Rays taken of your SI joints? If so, how long ago was it? You might need to have new ones taken. For most of us, this is where the first X-Ray signs appear. You should also mention the rib pain to your doctor. Do you have morning/nightly stiffness? You should mention that to your doctor as well. You might want to try and get a referral to a rheumy.
To answer to your heart attack vs rib pain symptoms, its not too difficult to differentiate them. A heart attack will usually cause shortness of breath, cold sweats, and pain that irradiates into your left arm (the pain will remain even if you hold your breath). A heart attack will not cause any palpable pain (there is no tender area because the pain is coming from under the rib cage).
Rib pains on the other hand should improve if you hold your breath (while your lungs are empty) and increase when you fill the lungs, cause quite a bit of pain if you touch the affected ribs, and rarely irradiate to other parts of the body.
Good luck, and welcome to KA.
Carole
