Yuhua Chen1, Mingxia Zheng2, Ke Lin1, Kaijun Cui3. 1. Department of Cardiovascular Surgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, Sichuan 610041, People's Republic of China. 2. Department of Cardiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, Sichuan 610041, People's Republic of China. 3. Department of Cardiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, Sichuan 610041, People's Republic of China cuikaijun@hotmail.com.