1. Department of Cardiology, Clinical Center of Serbia, 26 Višegradska, Belgrade, Serbia
2. School of Medicine, Belgrade University, 8 Dr Subotića, Belgarde, Serbia
3. Department of Electrophysiology, Heart Center, University of Leipzig, Struempellstr. 39, Leipzig, Germany
4. ANMCO (Associazione Nazionale Medici Cardiologi Ospedalieri) Research Center, Via La Marmora 36, Florence, Italy
5. Heart Failure Unit, Cardiology, G. da Saliceto Hospital, Via Taverna Giuseppe 49, Piacenza, Italy
6. Department of Cardiology, Heraklion University Hospital, Voutes 7100, Heraklion-Crete, Greece