1. Department of Electrocardiology, St. John Paul II Hospital, Prądnicka 80, 31-202 Kraków, Poland
2. Faculty of Medicine, Jagiellonian University Medical College, Św. Anny 12, 31-008 Kraków, Poland
3. Ordensklinikum Linz Elisabethinen, Fadingerstraße 1, 4020 Linz, Austria
4. Clinic for Electrophysiology, Herz- und Diabeteszentrum NRW, Georgstr. 11, 32545 Bad Oeynhausen, Germany
5. Department of Electrocardiology, Institute of Cardiology, Faculty of Medicine, Jagiellonian University Medical College, Prądnicka 80, 31-202 Kraków, Poland