1. From the Cardiac Arrhythmia Services, Southcoast Health System, Fall River, MA (N.S.); Cardiac Arrhythmia Service, Department of Cardiovascular Medicine, Lahey Hospital and Medical Center Burlington, MA (D.T.M.); and Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT (R.L., J.P.C., C.P., J.C.).