question: Hi, I recently saw a pulmonologist following 2 episodes of allergic reaction followed by cough induced asthma. My PFT was normal except for a low DLOC of 15.6. I still have some dyspnea on exertion, like stairs. I also feel tired sleep more than usual. I m 75 yrs old. I had a normal chest X-ray And Cat scan of my lungs. Could this be a cardiovascular problem? Thank you. Betty