I have the EXACT issues that you are having. I feel so good after doing 30 minutes on the elliptical and some toning stuff. My chest tightens as the day goes on and I thought maybe it was my underwire. I’ll just be sitting on the couch and my heart flutters to where I have to cough. It’s like it takes my breath away. My chest is constantly tight for 2 months now. It all started with these pains that felt like someone was poking me with a poker under my left breast. Pain sometimes radiates throughout my body. I get headaches. Numbness and tingling in my left arm and sometimes my legs. Dizziness. I have gone to the doctor and of course he prescribed anxiety meds and told me to go to a “Behavioral Therapist”. My bloodwork Great, my heart function great. My resting rate is around 62. I went and got a mammogram, per doctor request, fine. I am going for a heart monitor next month. Yep, takes that long. I honestly feel like it’s a blocked artery but my doctor doesn’’t Want to do the tests. He said that if I feel that bad to go to the emergency room and they will automatically run all the tests. I am so frustrated!