1. Cardiovascular Division, Department of Medicine, Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (M.B., A.S.-D., E.L., C.S., E.A.).
2. Division of Cardiovascular Medicine, Richard A. and Susan F. Smith Center for Cardiovascular Outcomes Research, Beth Israel Deaconess Medical Center, Boston, MA (C.S.).