1 The Permanente Medical Group, Kaiser Permanente Division of Research, Oakland, CA 94612, USA; CREST Network, Oakland, California, CA, USA. Electronic address: drvinson@ucdavis.edu.
2 Department of Emergency Medicine, Oregon Health and Science University, Portland, OR, USA.
3 Arrhythmia Division, Spanish Society of Emergency Medicine, Madrid, Spain; Emergency Area Research Group, Hospital Clinic, Barcelona, Spain.
4 Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.