title: I've been experiencing some shortness of breath while doing simple things around the house, like vacuuming or carrying the laundry upstairs. Tests of my lung function turned out normal. Now my doctor wants to check further for possible heart problems. Please explain how shortness of breath can be related to my heart.
mesh_terms: D004417:Dyspnea / Q000209:etiology*; D006331:Heart Diseases / Q000150:complications* / Q000175:diagnosis; D006801:Humans