1. From the Heart Rhythm Management Center (A.S., G.-B.C., G.P., T.B., C.D.A., M.R., S.H., P.B.), Universitair Ziekenhuis Brussels, Brussels, Belgium; the Department of Biostatistics and Medical Informatics (L.K., R.B.), Vrije Universiteit Brussel, Brussels, Belgium; the Cardiovascular Genetics Center (R.B.), University of Girona, Girona, Spain; and the Cardiology Department (J.B.), Thorax Institute, University of Barcelona, Barcelona, Spain.