1. Division of Cardiology, Department of Internal MedicineCollege of Medicine, Inje University, Seoul Paik Hospital Seoul Korea
2. Division of Cardiology, Department of Internal MedicineHeart Vascular and Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul Korea
3. Division of Cardiology, Department of MedicineVeterans Health Service Medical Center Seoul Korea
4. Division of Cardiology, Department of Internal MedicineKangwon National University College of Medicine Hospital Chuncheon Korea