1. Department of Cardiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
2. Department of Intensive Care Unit, People’s Hospital of Rizhao, Rizhao, Shandong 276800, China
3. Department of Cardiology, Qingdao Fu Wai Hospital of Cardiovascular Diseases, Qingdao 266034, China