*Corresponding author:
Liangrong Zheng
Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
E-mail: 1191066@zju.edu.cn (Liangrong Zheng)
Or
Yubin Zhang
Department of Electrocardiogram, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
E-mail:1714271@zju.edu.cn (Yubin Zhang)
Declarations of interest: none
Word Count: 1532 words (not including title, figure legends, references and acknowledgment)