1. Department of Internal Medicine, Hebei Medical University, Shijiazhuang, Hebei 050017, P.R. China
2. Department of Neurology, Hebei General Hospital, Shijiazhuang, Hebei 050051, P.R. China
3. Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei 050051, P.R. China