1. Department of Surgical and Perioperative Science, Division of Cardiothoracic Surgery at the University Hospital of Umeå, Umeå, Sweden,
2. Department of Surgical and Perioperative Science, Division of Cardiothoracic Surgery at the University Hospital of Umeå, Umeå, Sweden
3. Department of Behavioural Science, University of Linkö ping, Linköping, Sweden