[1] Sungkyunkwan Univ, Kangbuk Samsung Hosp, Dept Internal Med, Div Cardiol,Sch Med, Seoul 03181, South Korea
[2] Univ Ulsan, Asan Med Ctr, Dept Internal Med, Div Cardiol,Coll Med, Seoul 05505, South Korea
[3] Seoul Natl Univ Hosp, Dept Internal Med, Div Cardiol, Seoul 03080, South Korea
[4] Sungkyunkwan Univ, Dept Internal Med, Div Cardiol, Coll Med, Seoul 06351, South Korea
[5] Chungbuk Natl Univ, Dept Internal Med, Div Cardiol, Coll Med, Cheongju 28644, South Korea
[6] Kyungpook Natl Univ, Dept Internal Med, Div Cardiol, Coll Med, Daegu 41944, South Korea
[7] Catholic Univ Republ Korea, Dept Internal Med, Div Cardiol, Seoul 03083, South Korea
[8] Yonsei Univ, Dept Internal Med, Div Cardiol, Coll Med, Seoul 03722, South Korea
[9] Seoul Natl Univ, Bundang Hosp, Div Cardiol, Cardiovasc Ctr, Seongnam 13620, South Korea
[10] Yonsei Univ, Dept Internal Med, Wonju Coll Med, Div Cardiol, Wonju 26426, South Korea
[11] Chonnam Natl Univ, Heart Res Ctr, Gwangju 61469, South Korea