1 Cardiovascular Section, Department of Internal Medicine, Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma, USA. nagai10m@r6.dion.ne.jp.
2 Department of Cardiology, Hiroshima City Asa Hospital, Hiroshima, Japan. nagai10m@r6.dion.ne.jp.
3 University Hospital Würzburg, Department of Anaesthesiology, Intensive Care, Emergency and Pain Medicine, Würzburg, Germany.