1 Division of Cardiology, Department of Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA.
2 Department of Emergency Medicine, VA Medical Center Puget Sound, Seattle, WA, USA; Harborview Medical Center, Seattle, WA, USA.
3 Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA. Electronic address: eagill@u.washington.edu.