1. Faculty of Medicine University of Iceland Reykjavik Iceland
2. Internal Medicine Services Landspitali–The National University Hospital of Iceland Reykjavik Iceland
3. Division of Cardiology Landspitali–The National University Hospital of Iceland Reykjavik Iceland
4. Department of Anesthesia and Intensive Care Medicine, Operational Services Landspitali–The National University Hospital of Iceland Reykjavik Iceland