Male 27 smoker,average to slim, 6 ft 5. Problem been ongoing for 8 years on and off. Doesn't happen during exercise or when laying down but usually at rest when I first get up from sitting down. Sudden shortness of breath which usually lasts a couple of seconds, feels like its coming from right lung, broke 5 ribs before on right side of chest. Usually happens after I smoked a lot the night before. May go months without episodes, stopped pretty much completely when I didn't smoke. Went to doctor two years ago he said it was probably smoking related. I don't have chest pain or a cough with it, nor dizziness or palapatations. Happened last one month ago and I asked on an online forum and was told it was probably heart related. Ever since I've been a nervous wreck. From what I described does it seem likely or unlikely to heart related?