1. Department of Cardiology, Linköping University Hospital, S-58185 Linköping, Sweden
2. Department of Medicine and Health Sciences, Division of Cardiovascular Medicine, Faculty of Health Sciences Linköping University, S-58185 Linköping, Sweden
3. Department of Medicine and Health Sciences, Faculty of Health Sciences Linköping University, S-58185 Linköping, Sweden
4. School of human sciences, University of Kalmar, S-39182 Kalmar, Sweden
5. Department of Clinical and Experimental Medicine, Division of Clinical Neurophysiology, Faculty of Health Sciences Linköping University, S-58185 Linköping, Sweden
6. Department of Clinical Neurophysiology, Linköping University Hospital, S-58185 Linköping, Sweden
7. Department of Nursing Science, School of Health Sciences, Jönköping University, 551 85 Jönköping, Sweden