Gao, Chuanyu, Department of Cardiology, People’s Hospital of Zhengzhou University, No. 7 Weiwu Road, Jinshui District, Zhengzhou 450003, Henan Procince, China; Tel: +86 0371-58680639, Fax: +86 0371-58680639; E-mail: gaochuanyuz@163.com, China