1. Division of Electrophysiology Texas Cardiac Arrhythmia Institute, St. David's Medical Center Austin Texas USA
2. Department of interventional electrophysiology Interventional Electrophysiology, Scripps Clinic San Diego California USA
3. Department of Internal Medicine Metro Health Medical Center, Case Western Reserve University School of Medicine Cleveland Ohio USA
4. Division of Cardiology, Department of Biomedicine and Prevention University of Tor Vergata Rome Italy