[1] Rush Univ, Med Ctr, Chicago, IL 60612 USA
[2] Duke Univ, Durham, NC USA
[3] Univ Calif Los Angeles, Div Cardiol, Los Angeles, CA USA
[4] Univ Calgary, Calgary, AB, Canada
[5] Brigham & Womens Hosp, 75 Francis St, Boston, MA 02115 USA
[6] MGH, Dept Neurol, Boston, MA USA
[7] Univ Calif Los Angeles, Sch Med, Los Angeles, CA USA