... Within 2 weeks I had lost 75% of my cardio capacity with sever burning pain on exertion. Since then a number of treatments (prednisone, asthma inhalers, antibiotics, etc.) have had varying degrees of effect, but never back to even 50%. xrays, CT show nothing... no discernible sound when dr listens. I'm interested in anyone else who as had similar issues. There is no other potential cause... devastating condition. middle aged fit male... thanks