1. Department of Medicine, Unit of Cardiology, Karolinska Institutet , D1:04, 171 76 Stockholm , Sweden
2. Heart and Vascular Theme, Karolinska University Hospital , Norrbacka, S1:02, 171 76 Stockholm , Sweden
3. Department of Physiology and Pharmacology, Karolinska Institutet , Biomedicum, Solnavägen 9 171 65 Solna , Sweden
4. Perioperative Medicine and Intensive Care, Karolinska University Hospital , 171 76 Stockholm , Sweden
5. Department of Clinical Physiology, Sunderby Hospital , 971 80 Luleå , Sweden
6. Department of Medical Sciences, Gastroenterology and Hepatology, Uppsala University , 751 05 Uppsala , Sweden