[1] Kangwon Natl Univ, Dept Internal Med, Div Cardiol, Sch Med, 156 Baengnyeong Rd, Chunchon 24289, South Korea
[2] Chonnam Natl Univ Hosp, Cardiovasc Ctr, Dept Cardiol, Gwangju, South Korea
[3] Yonsei Univ, Severance Cardiovasc Hosp, Div Cardiol, Coll Med, Seoul, South Korea
[4] Soonchunhyang Univ, Cardiol Dept, Cheonan Hosp, Cheonan, South Korea
[5] Inje Univ, Haeundae Paik Hosp, Div Cardiol, Coll Med, Busan, South Korea
[6] Inje Univ, Sanggye Paik Hosp, Dept Internal Med, Div Cardiol,Coll Med, Seoul, South Korea