Cause for Shortness of breath after walking 50 ft and/or at rest

My husband (49 yrs old in excellent shape) just recently developed shortness of breath accompanied with chest pain (right on the sternum) on exertion and now even at rest (walking or going up and down stairs would triggger it). History wise, he was diagnosed with Pulmonary Stenosis at six years old. Because of a healthy lifestyle he led since he was a teenager, this disease did not progress. He is a Purchasing manager. He does not smoke but he drinks 3-4 glasses of wine every night (he cut back to 2 glasses recently).

His SOB started after Christmas 2010, month of January he noticed his aerobic capacity been progressively diminished each week. He would go to the gym every weekend to work out and would get on elliptical for 15 minutes to warm up before lifting weights (he was a professional powerlifter for a long time). In January he noticed it was getting harder and harder to use the eliptical machine. He went from 15 minutes to 5 mins then to 2 mins and two months later even walk from his car to his office will make him out breath and tired. It would take between 5-10 minutes for him to recover. Some other days he would have so many SOB episodes that it made him so tired and would sleep a lot 12 - 15 hours or more if he can.

I took him to ER the first time he had an episode thinking it was a heart attack, we went to ER a couple more times, each time, his heart would check out fine. After a nuclear stress test, CTA, Echo his cardiologist  thinks his heart is fine. His pulmonary artery is slightly enlarged but the doctor said it's normal for somebody who has pulmonary stenosis. He had an ultrasound at the ED of his liver, gallbladder and kidney and the only thing worth mentioning was the slight fatty infiltration in the liver but according to gastroenterolgist it should not cause his SOB. His chest X- ray was normal too. He saw a Pulmonologist on March 1st, he did a six minute walk test, he collapsed after 4 mins, his BP went up from 117/75 to 150/95 and his oxygen level was at 98. The pulmonologist suggested that he sees a Psychiatrist because his lungs are fine.

We are going to schedule another GI endoscopy (he had one 2 yrs ago and test was normal except of small lesion on his upper esophagus)

We are getting frustrated about this and could really use some fresh perspective. We would really appreciate any comments or suggestions.

Thank you,

V

[curmudgen]

No evidence of heart disease, lung disease, O2 levels normal with exercise.
Possible esophagitis. ONLY symptom - shortness of breath while exercising.  

I don't understand doing the endoscopy.  Assuming no diabetes, a normal blood chemistry, normal electrolytes, normal blood pH after exercising (no metabolic acidosis)....  the one thing that comes to mind is the possibility of a restricted blood flow to the brain during exercise that is causing the sensation of SOB.  Have they done a doppler on his carotid arteries?  I would reconfirm with cardiologist that "thinks his heart is fine." There is some ambiguity in that comment.  ( former Bio Prof playing doctor.)