1. Department of Electrocardiogram Diagnosis, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
2. Department of Cardiovascular Medicine, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
3. Department of Cardiovascular Ultrasonic Center, The First Affiliated Hospital of Zhejiang University, The First Hospital of Zhejiang Province, Hangzhou, Zhejiang 310003, P.R. China