1. Department of Cardiology, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
2. Department of Psychology, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
3. Department of Cardiovascular Medicine, Yidu Central Hospital of Weifang, Weifang, Shandong 262500, P.R. China
4. Weifang People's Hospital, Weifang, Shandong 261041, P.R. China