1. Second Department of Internal Medicine, University of Occupational and Environmental Health, Japan
2. Department of Cardiology, Kokura Memorial Hospital
3. Department of Echocardiography, Asan Medical Center
4. Department of Echocardiography, Kokura Memorial Hospital
5. Department of Clinical Laboratory, The Sakakibara Heart Institution of Okayama
6. Department of Cardiology, The Sakakibara Heart Institution of Okayama
7. Department of Cardiovascular Surgery, University of Occupational and Environmental Health, Japan
8. Department of Cardiovascular Surgery, Kokura Memorial Hospital
9. Cardiac Ultrasound Laboratory, Massachusetts General Hospital