creators_name: Shirayama, Takeshi editors_name: Singh, Balbir editors_name: Lokhandwala, Yash editors_name: Francis, Johnson editors_name: Gupta, Anup type: journalp datestamp: 2005-04-20 lastmod: 2011-03-11 08:55:58 metadata_visibility: show title: Role of Atrial Fibrillation Threshold Evaluation on Guiding Treatment ispublished: pub subjects: ipej full_text_status: public keywords: atrial fibrillation, electrophysiological test, therapy, prognosis abstract: Atrial fibrillation could be induced reproducibly by 50Hz rapid stimulation which was given through systolic and early diastolic phase of atrial excitation. Duration of atrial fibrillation induced in this way was roughly dependent on the current amplitude of the stimulation. The minimum current that could induce long-lasting atrial fibrillation (30sec in the clinical setting, 2sec in the rabbit or rat model) was defined as atrial fibrillation threshold (AFT). AFT was larger in patients who had history of atrial fibrillation than those who did not. Anti-arrhythmic drugs raised AFT by various degrees both in experimental and clinical cases. Long-term efficacy of a drug could be predicted in a patient, measuring how much the drug increased AFT (cut-off point = 5mA increase). AFT is a useful marker to evaluate atrial vulnerability and to guide pharmacological treatment of atrial fibrillation. date: 2003-10 date_type: published publication: Indian Pacing and Electrophysiology Journal volume: 3 number: 4 publisher: Indian Pacing and Electrophysiology Group pagerange: 224-230 refereed: TRUE referencetext: 1. Khairy P, Nattel S. New insights into the mechanisms and management of atrial fibrillation. CMAJ 2002;167(9):1012-1020. 2. Bosch RF, Nattel S. Cellular electrophysiology of atrial fibrillation. Cardiovasc Res 2002;54(2):259-269. 3. Nattel S, Li D, Yue L. Basic mechanisms of atrial fibrillation--very new insights into very old ideas. 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[Journal (Paginated)] document_url: http://cogprints.org/4248/1/shirayama.htm