[1] Korea Univ, Guro Hosp, Ctr Cardiovasc, Div Cardiol, Seoul 152703, South Korea
[2] Chung Ang Univ Hosp, Div Cardiol, Seoul, South Korea
[3] Korea Univ, Ansan Hosp, Div Cardiol, Ansan, South Korea
[4] Hallym Univ, Hangang Sacred Heart Hosp, Div Cardiol, Seoul, South Korea
[5] Utah Valley Reg Med Ctr, Div Cardiol, Provo, UT USA