1. From the Texas Cardiac Arrhythmia Institute, St. David’s Medical Center, Austin, TX (P.S., L.D.B., A.N.); Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, PA (P.S.); Cardiovascular Division, Albert Einstein School of Medicine at Montefiore Hospital, New York, NY (L.D.B.); and Cardiology Department, University of Foggia, Foggia, Italy (P.S., L.D.B.).