[1] Zhejiang Univ, Sch Med, Hangzhou, Zhejiang, Peoples R China
[2] Zhejiang Univ, Sch Med, Affiliated Hosp 2, Dept Cardiol, Hangzhou 310009, Zhejiang, Peoples R China
[3] Zhejiang Univ, Sch Med, Affiliated Hosp 2, Dept Echocardiog, Hangzhou, Zhejiang, Peoples R China
[4] Guangdong Peoples Hosp, Dept Cardiol, Guangzhou, Guangdong, Peoples R China