1. Department of Cardiology Stavanger University Hospital Stavanger Norway
2. Clinical Institute II University of Bergen Bergen Norway
3. Department of Mathematics and Physics The University of Stavanger Stavanger Norway
4. Research Department Stavanger University Hospital Stavanger Norway
5. Departement of Biochemistry Stavanger University Hospital Stavanger Norway
6. Department of Biochemistry Haukeland University Hospital Bergen Norway
7. Department of Medical Biosciences, Exercise Physiology Research Group Radboud University Medical Center Nijmegen the Netherlands
8. Department of Electrical Engineering and Computer Science University of Stavanger Stavanger Norway