1. Department of Cardiology and Pulmonary Medicine; University Medical Center Göttingen; Göttingen Germany
2. Institute of Cardiovascular Physiology; University Medical Center Göttingen; Göttingen Germany
3. Department of Transfusion Medicine; University Medical Center Göttingen; Göttingen Germany
4. Medical Clinic 2; Department of Cardiology; University Medical Center Mainz; Mainz Germany