Universitaire Ziekenhuisen Leuven, Leuven, Belgium
Clinique Jules Verne, Nantes, Cedex 3, France
Hopital Edouard Herriot, Lyon Cedex 03, France
Torrance Memorial Medical Center, Torrance, California, United States
Advanced Cardiac Specialists, Mesa, Arizona, United States
NEA Baptist Memorial Hospital, Jonesboro, Arkansas, United States
Katholisches Krankenhaus, St.Johannes Hospital, Hagen, Germany
Cardiac Device Rhythm Specialists, Los Angeles, California, United States
Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
Baltimore Heart Association, Randallstown, Maryland, United States
University of Rochester (Multiple Facilities Participating World Wide), Rochester, New York, United States
Kerckhoff-Klinik GmbH, Bad Nauheim, Hessen, Germany
St. Vincent's Hospital, Indianapolis, Indiana, United States
Cleveland Clinic, Cleveland, Ohio, United States
Wellstar Kennestone Hospital, Marietta, Georgia, United States
University of Cologne, Cologne, Germany
Danish Headache Center, Glostrup, Denmark
The City of London Migraine Clinic, London, United Kingdom
Norwegian National Headache Centre, Trondheim, Norway