1. Schuechtermann-Clinic, Department of Cardiology, Heart-Center Osnabrueck-Bad Rothenfelde, Ulmenallee 5-11, D-49214 Bad Rothenfelde, Germany
2. Schuechtermann-Clinic, Department of Heart Surgery, Heart-Center Osnabrueck-Bad Rothenfelde, Ulmenallee 5-11, D-49214 Bad Rothenfelde, Germany