1 Division of Cardiology, Department of Internal Medicine, Yeungnam University Medical Center, Daegu, Republic of Korea.
2 Department of Epidemiology and Biostatistics, Institute of Computational Health Sciences, University of California San Francisco, San Francisco, California.
3 Division of Cardiology, Section of Electrophysiology, University of California San Francisco, San Francisco, California. Electronic address: Melvin.Scheinman@ucsf.edu.