1. Department of Cardiology, Alfried Krupp Krankenhaus, Alfried-Krupp-Str. 21, Essen, Germany
2. University of Witten/Herdecke, Department of Health, Alfred-Herrhausen-Straße 50, Witten, Germany
3. Department of Cardiology and Vascular Medicine, West-German Heart and Vascular Center Essen, University Duisburg-Essen, Holsterhauser Str. 55, Essen, Germany
4. Institute of Medical Informatics, Biometry, and Epidemiology, University Duisburg-Essen, Holsterhauser Str. 55, Essen, Germany
5. Department of Electrophysiology, Alfried Krupp Krankenhaus, Alfried-Krupp-Str. 21, Essen, Germany
6. Institute for Occupational, Social and Environmental Medicine, Centre for Health and Society, Medical Faculty, University of Düsseldorf, Gurlittstr. 55 / II, 40223 Düsseldorf, Germany