title: [Use of echocardiography in the study of the Björk-Shiley disk valve prosthesis].
mesh_terms: D001021:Aortic Valve; D004452:Echocardiography; D006349:Heart Valve Diseases / Q000601:surgery; D006350:Heart Valve Prosthesis; D006801:Humans; D008943:Mitral Valve
vernacular_title: L'impiego dell'ecocardiografia nello studio delle protesi valvolari a disco di Björk-Shiley