title: I recently started using supplemental oxygen because I have chronic obstructive pulmonary disease (COPD). I'm still fairly active, but I'm concerned about an upcoming mitral valve operation. How will relying more on supplemental oxygen affect my heart and circulation?
mesh_terms: D006348:Cardiac Surgical Procedures; D006801:Humans; D008943:Mitral Valve / Q000601:surgery; D010100:Oxygen; D029424:Pulmonary Disease, Chronic Obstructive
chemical_list: D010100:Oxygen