1. Department of Emergency, The People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
2. Department of Emergency, The People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
3. Department of Medical, The People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
4. Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, P.R. China
5. Department of Cardiology, The People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China