1. Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Olav Kyrres gt. 3, 7489 Trondheim, Norway.
2. Department of Cardiology, St. Olavs Hospital, 7006 Trondheim, Norway.
3. Department of Pharmacology, Cardiovascular Biology, and Metabolic Diseases, Medical College of Ohio, 3035 Arlington Avenue, Toledo, OH 43614–5804, USA.
4. Department of Biology, Williams College, Williamstown, MA 01267, USA.
5. Department of Physical Medicine and Rehabilitation, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48109–0718, USA.