title: Dyspnea on exertion. Is it the heart or the lungs?
mesh_terms: D002245:Carbon Dioxide / Q000097:blood; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology*; D006321:Heart / Q000503:physiopathology*; D006331:Heart Diseases / Q000150:complications; D006439:Hemodynamics; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000150:complications; D008954:Models, Biological; D009132:Muscles / Q000503:physiopathology; D010101:Oxygen Consumption; D005082:Physical Exertion
chemical_list: D002245:Carbon Dioxide