1. Department of Internal Medicine, Division of Cardiology; Medical University Graz; Auenbruggerplatz 15 Graz 8036 Austria
2. Institute of Cardiac Diagnostics and Therapy; Moltkestrasse 31 Berlin 12203 Germany
3. Department of Anaesthesiology and Intensive Care Medicine; Medical University Graz; Auenbruggerplatz 29 Graz 8036 Austria
4. Department of Surgery, Division of Cardiac Surgery; Medical University Graz; Auenbruggerplatz 29 Graz 8036 Austria