1. Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
2. School of Clinical and Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
3. Department of ECG Information, Shandong Engineering Research Center, Jinan, Shandong, China
4. Department of Chronic Disease, Centers for Disease Control of Hanting District, Weifang, Shandong, China
5. Department of Cardiology, Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China