1. Department of Cardiology, University Witten/Herdecke, 58455 Witten, Germany
2. Faculty of Medicine, Semmelweis University, 1085 Budapest, Hungary
3. Cardiology and Rhythmology, Ev. Krankenhaus Hagen, 58135 Hagen, Germany
4. Department of Cardiology and Angiology, Bergmannsheil University Hospitals, Ruhr University of Bochum, 44789 Bochum, Germany
5. Department of Cardiology and Angiology, Marienhospital Gelsenkirchen, 45886 Gelsenkirchen, Germany
6. Department of Cardiology, Elektrophysiology and Angiology, Klinikum Lüdenscheid, 58515 Luedenscheid, Germany
7. Department of Cardiology, Helios Klinikum Wuppertal, 42283 Wuppertal, Germany
8. Faculty of Health, Institute for Medical Biometry and Epidemiology, Witten/Herdecke University, 58455 Witten, Germany