1. Department of Material supply, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China
2. Department of Cardiology, First Ward, Yantai Yeda Hospital, Yantai, Shandong, China
3. Department of Cardiovascular medicine, Weihai Municipal Hospital, Weihai, Shandong, China
4. Department of Cardiology, the Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China