1 Cardiomyopathy Unit, Careggi University Hospital, 1011 Florence, Italy.
2 Department of Cardiology, University Hospital of Lausanne, Rue de Bugnon 46, Switzerland.
3 Department of Cardiovascular, Neural and Metabolic Sciences, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, IRCCS Istituto Auxologico Italiano, San Luca Hospital, Milan, Italy.