Intracardiac Phonocardiography in Mitral and Aortic Value LesionsLUISADA, A. A. M.D.LIU, C. K. M.D.Author informationFrom the Division of Cardiology of the Chicago Medical School at Mount Sinai Hospital, Chicago, Ill.Circulation 18(5):p 989-990, November 1958.Copyright © 1958 American Heart Association, Inc.