1. Department of Cardiology; Sahlgrenska University Hospital; SE-41345 Gothenburg Sweden
2. Department of Cardiology; Linkoping University Hospital; S-582 52 Linkoping Sweden
3. Department of Cardiology; Rikshospitalet University Hospital; 0027 Oslo Norway
4. Department of Critical Care; R&D, Orion Pharma; PO Box 65 02101 Espoo Finland
5. Department of Cardiology, Södersjukhuset; Sjukhusbacken 10 Stockholm Sweden
6. Department of Medical Sciences, Kardiologi; Akademiska Hospital, Institution of Medical Science; Uppsala 751 85 Sweden