I've come to believe that I've experienced plenty of symptoms of stress/anxiety, due to my body's fighting balance problems. Looking back, I think the very first symptom of my AN that I noticed was a general decline in energy. Even when I haven't been noticing "wonky headedness" or balance difficulties, I think they're present, and I think they take a toll on one's system.
Also, I've had some problems with esophageal spasm, supposedly related to meds that I take/have taken, and this tightness definitely feels like heart stuff. However, my doctor did order a stress test just to be on the safe side, and this came back normal.
This is one of the most frustrating parts of the whole AN experience for me - lots of weird, odds & ends symptoms which may or may not be related, and generally not feeling well. Very glad to hear you're staying so active. I'm a triathlete, and after my CK one year ago, I experienced a long, slow slide in terms of my fitness. Hoping to work on improving that this spring! Take care, and let us know what all you find out.