1. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
2. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
3. Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Medtronic Korea, Ltd., Seoul, Korea.
5. Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Chest and Heart Hospital, Liverpool, United Kingdom.
6. Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.