1. Department of Cardiology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Japan
2. Institute for Clinical Research, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Japan
3. Department of Diagnostic Pathology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Japan
4. Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Japan