1. From the Cardiac Arrhythmia Research Centre (M.C., C.C., A.D.R., F.T., S.B., F.G., C.T.) and Intensive Care Unit (I.M.), Centro Cardiologico Monzino, IRCCS, Milan, Italy, and Radiology Department (L.M.), IRCCS Istituto Clinico Humanitas, Rozzano (Milan), Italy.