1. Department of Cardiology and Clinical Examination, Faculty of Medicine, Oita University , 1-1 Idaigaoka, Hasama, Yufu-city 879-5593 , Japan
2. Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center , Osaka , Japan
3. Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science , Shiga , Japan