1. INOVA Fairfax Hospital; Fairfax Virginia USA
2. Texas Cardiac Arrhythmia Institute; Austin Texas USA
3. Temple University Health System; Philadelphia Pennsylvania USA
4. Stern Cardiovascular Foundation; Memphis Tennessee USA
5. University of Southern California; Los Angeles California USA
6. Brigham and Women's Hospital; Boston Massachusetts USA
7. St. Jude Medical; Sylmar California USA
8. Ohio State University; Columbus Ohio USA