1. Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
2. Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
3. Department of Medicine, Cardiac Arrhythmia Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
4. Department of Medicine, Cardiac Arrhythmia Center, VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd 111E, Los Angeles, CA 90073, USA
5. Department of Medicine, Division of Pulmonary and Critical Care Medicine, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
6. Department of Medicine, Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA