1. Cardiac Rythm Management Boston Scientific St Paul Minnesota USA
2. Cardiac Arrhythmia Service Florida Atlantic University CESCOM Boca Raton Florida USA
3. Department of Cardiology, Erlanger Hospital University of Tennessee Knoxville Tennessee USA
4. Department of Clinical Medicine University of Missouri School of Medicine Columbia Missouri USA
5. Yakima Heart Lung & Vascular Clinic Yakima Valley Memorial Yakima Washington USA