1. From the Division of Cardiac Electrophysiology, Johns Hopkins Heart and Vascular Institute, Baltimore, MD (A.S.J.M.t.R., H.T.); Division of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands (A.S.J.M.t.R.); and UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center of Excellence (O.A.A., K.S.).