1. Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine
2. Department of Cardiology, Tohoku Kosai Hospital
3. Department of Cardiology, Osaki City Hospital
4. Second Department of Internal Medicine, Hiraka General Hospital
5. Department of Cardiology, Katta General Hospital
6. Second Department of Internal Medicine, Towada Municipal Central Hospital
7. Department of Cardiology, Sendai Medical Center