[1] Hunan Univ, Xiangtan Cent Hosp, Affiliated Hosp, Med Dept, Xiangtan 411100, Peoples R China
[2] Hunan Univ, Xiangtan Cent Hosp, Affiliated Hosp, Dept Pulm & Crit Care Med, Xiangtan 411100, Peoples R China
[3] Hunan Univ, Xiangtan Cent Hosp, Affiliated Hosp, Dept Cardiol, Xiangtan 411100, Peoples R China