1. Department of Cardiology and Clinical Examination, Faculty of Medicine Oita University Oita Japan
2. Department of Medicine II Kansai Medical University Moriguchi Japan
3. Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine National Cerebral and Cardiovascular Center Osaka Suita Japan
4. Cardiovascular Division, Department of Internal Medicine, Institute of Clinical Medicine University of Tsukuba Tsukuba Japan
5. Division of Cardiology St. Luke's International Hospital Tokyo Japan
6. Department of Internal Medicine Senri Central Hospital Suita Japan
7. Department of Cardiovascular Medicine Tokyo Medical and Dental University Tokyo Japan