1. Department of Cardiology, Rigshospitalet, University of Copenhagen , Copenhagen, Blegdamsvej 9, 2100 København Ø , Denmark
2. Department of Cardiology, Zealand University Hospital , Sygehusvej 10, 4000 Roskilde , Denmark
3. Department of Cardiology, Aalborg University Hospital , Hobrovej 18-22, 9000 Aalborg Denmark
4. Department of Cardiology, Aarhus University Hospital Skejby , Palle Juul-Jensens Boulevard 99, 8200 Aarhus N , Denmark