1 From the Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (P.H.S.); and Mechanical and Industrial Engineering Department, Northeastern University, Boston, MA (A.U.C.). pstone@partners.org.
2 From the Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (P.H.S.); and Mechanical and Industrial Engineering Department, Northeastern University, Boston, MA (A.U.C.).