1. Department of Electrophysiology, Alfried Krupp Krankenhaus , Alfried-Krupp-Straße 21, 45131 Essen , Germany
2. Department of Medicine, Witten/Herdecke University , Alfred-Herrhausen-Straße 50, 58448 Witten , Germany
3. Department of Cardiology, St. Marienhospital Vechta , Vechta , Germany
4. Department of Oncology, Gastroenterology and Hematology, Alfried Krupp Krankenhaus , Essen , Germany