1. Medical College, Guizhou University, Guiyang, Guizhou 550025, P.R. China
2. Department of Cardiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou 550002, P.R. China
3. Department of Clinical Laboratory, Guizhou Provincial People's Hospital, Guiyang, Guizhou 550002, P.R. China