1. Department of Medicine; Faculty of Medicine Siriraj Hospital; Mahidol University; Bangkok Thailand
2. Department of Internal Medicine; Bassett Medical Center and Columbia University College of Physicians and Surgeons; Cooperstown New York USA
3. Department of Physiology, Cardiac Electrophysiology Unit; Faculty of Medicine; Chiang Mai University; Chiang Mai Thailand
4. Cardiac Electrophysiology Research and Training Center; Faculty of Medicine; Chiang Mai University; Chiang Mai Thailand
5. Department of Medicine; Division of Nephrology and Hypertension; Mayo Clinic; Rochester Minnesota USA