1. Division of Cardiology, Montefiore Medical Center; Albert Einstein College of Medicine; Bronx NY USA
2. Division of Cardiology; Brown University; Providence RI USA
3. Division of Cardiology, Massachusetts General Hospital; Harvard Medical School; Boston MA USA
4. Texas Cardiac Arrhythmia Institute; St. David's Medical Center; Austin TX USA
5. Ahmanson-UCLA Cardiomyopathy Center; University of California; Los Angeles CA USA
6. Brigham and Women's Hospital; Harvard Medical School; Boston MA USA