[1] Univ Michigan, Ann Arbor, MI 48109 USA
[2] Georgetown Univ, Washington, DC USA
[3] Johns Hopkins Univ, Baltimore, MD USA
[4] Univ Minnesota, Minneapolis, MN USA
[5] Columbia Univ, New York, NY USA
[6] Texas Heart Inst, Houston, TX 77025 USA
[7] Massachusetts Gen Hosp, Boston, MA 02114 USA
[8] Thoratec Corp, Pleasanton, CA USA