1. Division of Cardiology, Internal Medicine III, Hamamatsu University School of Medicine , 1-20-1 Handayama, Higashi-ward, Hamamatsu 431-3192 , Japan
2. Department of Cardiology, Chutoen General Medical Center , 1-1 Shobugaike, Kakegawa, 436-0040 , Japan
3. Department of Cardiology, Juntendo University Shizuoka Hospital , 1129 Nagaoka, Izunokuni, 410-2211 , Japan
4. Department of Cardiovascular Medicine, Shizuoka Medical Center , 762-1 Nagasawa, Sunto-gun, 411-8611 , Japan
5. Department of Cardiology, Seirei Mikatahara General Hospital , 3453 Mikatahara-cho, Kita-ward, Hamamatsu, 433-8558 , Japan
6. Department of Cardiology, Seirei Hamamatsu General Hospital , 2-12-1 Sumiyoshi, Naka-ward, Hamamatsu, 430-0906 , Japan
7. Department of Cardiology, Hamamatsu Medical Center , 328 Tomitsuka-cho, Naka-ward, Hamamatsu, 432-8580 , Japan
8. Division of Arrhythmology, Shizuoka Saiseikai General Hospital , 1-1-1 Kojika, Suruga-ward, Shizuoka, 422-8021 , Japan
9. Department of Cardiology, Kameda Medical Center , 929 Higashi-cho, Kamogawa, 296-8602 , Japan
10. Department of Cardiology, Shintoshi Hospital , 703 Nakaizumi, Iwata, 438-0078 , Japan
11. Center for Clinical Research, Hamamatsu University Hospital , 1-20-1 Handayama, Higashi-ward, Hamamatsu, 431-3125 , Japan