[1] Univ Texas Med Branch, Dept Cardiovasc Med, Galveston, TX 77555 USA
[2] Massachusetts Gen Hosp, Div Cardiol, Boston, MA 02114 USA
[3] Harvard Med Sch, Boston, MA 02115 USA
[4] Rochester Gen Hosp, Dept Internal Med, Rochester, NY 14621 USA
[5] Univ South Carolina, Div Cardiovasc Med, Charleston, SC USA
[6] Abbott NW Hosp, Minneapolis Heart Inst, Minneapolis, MN USA
[7] Univ Calif San Francisco, Div Cardiovasc Med, San Francisco, CA 94143 USA
[8] Houston Med Ctr, Dept Internal Med, Warner Robins, GA USA
[9] Univ Kentucky, Dept Cardiovasc Med, Lexington, KY USA
[10] Baylor Sch Med, Div Cardiovasc Med, Houston, TX USA
[11] Univ Texas South Western, Div Cardiovasc Med, Dallas, TX USA