title: An improved pivotal disc-type prosthetic heart valve.
mesh_terms: D001021:Aortic Valve / Q000601:surgery; D005069:Evaluation Studies as Topic; D006350:Heart Valve Prosthesis / Q000009:adverse effects* / Q000592:standards; D006439:Hemodynamics; D006801:Humans; D011474:Prosthesis Design; D013923:Thromboembolism / Q000209:etiology