RT Journal Article SR Electronic T1 Prosthetic Ball Free in the Left Ventricle in a Patient with an Aortic Starr-edwards Prosthesis JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 565 OP 565 VO 55 IS 6 A1 James J. Acker YR 1988 UL http://www.ccjm.org/content/55/6/565.2.abstract AB