1. Department of Cardiology and Geriatrics, Kochi Medical School Kochi University Oko‐cho, Nankoku‐shi Kochi 783‐8505 Japan
2. Department of Cardiology Chikamori Hospital Kochi Japan
3. Department of Cardiology Kochi Health Sciences Center Kochi Japan
4. Department of Cardiology Japanese Red Cross Kochi Hospital Kochi Japan
5. Department of Cardiology Tosa Municipal Hospital Tosa Japan
6. Department of Cardiology Susaki Kuroshio Hospital Susaki Japan
7. Department of Cardiology Kochi Prefectural Aki General Hospital Kochi Japan
8. Department of Cardiology Kochi Prefectural Hata Kenmin Hospital Kochi Japan