Hi, I have had the same syptoms. I went to numerous doctors ekg, heart and lung cat scans, etc..everything came back perfect. However I still felt like i couldnt breathe and had chest pains (feeling of having a heart attack). I had shortness of breath that didnt go away. My GI docotor told me it was all in my head, my pulmonary doctor said "go on a vaction". I finally found a good GI guy and got an endoscopy. I had GERD..gastritus and damaged esophagus from the acid. I also found a great pulmonologist. He explained to me why GERD causes shortness of breath. Basically as the acid aspirates or spews into your esophogus and trachea, the fumes from the acid is breathed into your lungs causing slight or microscopic swelling which cannot be seen by standard tests!!! I was put on nexium 40 milligrams twice a day which stopped the pain in my chest and stomach after 3 weeks. However I still had shortness of breath. The new pulmonologist told me to go to the local store and buy Gaviscon. I bought the tablets and was on nexium twice a day, donatal (helps with esophagul spasms when acid is spewing into it causing chest pain and tightness) and GAVISCON two to four tablets (chewable not liquid) after i ate so about 4 times a day. It's the ONLY medication out there that has the power to coat your esophagus. Miraculously, after 3 days the shortness of breath subsided!!!! I had been yawning and bring up my diaphram to breath for months til i discovered GAVISCON! i'm telling you it WORKS! I have stayed in bed, taken all the meds and feel so much better!