[1] Brigham & Womens Hosp, Dept Med, Boston, MA 02115 USA
[2] Wake Heart Associates, Dept Med, Raleigh, NC USA
[3] Baystate Med Ctr, Dept Med, Springfield, MA 01199 USA
[4] London Chest Hosp, Dept Med, London E2 9JX, England
[5] Biogen Inc, Dept Med, Cambridge, MA 02142 USA