title: Frequency spectrum of the aortic component of the second heart sound in patients with normal valves, aortic stenosis and aortic porcine xenografts. Potential for detection of porcine xenograft degeneration.
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve / Q000502:physiology*; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology*; D001705:Bioprosthesis; D005260:Female; D006326:Heart Auscultation; D006347:Heart Sounds; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000503:physiopathology; D013997:Time Factors