[1] Chungnam Natl Univ, Chungnam Natl Univ Hosp, Dept Thorac & Cardiovasc Surg, Sch Med, Daejeon, South Korea
[2] Univ Ulsan, Asan Med Ctr, Dept Thorac & Cardiovasc Surg, Coll Med, 88 Olymp Ro 43 Gil, Seoul 138736, South Korea
[3] Univ Ulsan, Asan Med Ctr, Dept Cardiol, Coll Med, Seoul, South Korea
[4] Univ Ulsan, Asan Med Ctr, Div Pediat Cardiac Surg, Coll Med, Seoul, South Korea