Heterogeneous changes in electrophysiologic properties in the paroxysmal and chronically fibrillating human atrium

Heterogeneous Changes in Atrial Electrophysiologic Properties. introduction : The regional changes in atrial electrophysiologic properties related to a trial fibrillation (AF) in patients with paroxysmal AF (PAF) and chronic AF (CAF) remain unclear, The purpose of this study was to investigate the reg ional changes in atrial electrophysiology in patients with AF, Methods and Results: We evaluated the atrial electrophysiology at different sites thigh right atrium, low right atrium [LRA], and distal coronary sinu s [DCS]) in 11 patients with CAF, 8 patients with PAF, and 10 controls. Pat ients with CAF had significantly prolonged interatrial conduction and corre cted sinus node recovery time, and shortened atrial effective refractory pe riod (ERP) with loss of rate-related adaptation in the DCS, but had paradox ic prolongation of atrial ERP in the LRA, as compared with patients with PA F and the controls. As a result, the spatial distribution of atrial ERP tha t was observed in the controls and in patients with PAF was reversed in pat ients with CAF, without an increase in the dispersion of atrial refractorin ess, Patients with PAF showed intermediate changes in atrial conduction tim es and atrial refractoriness as compared with patients with CAF and control s. Conclusion: There was a regional heterogeneity on the changes of atrial ele ctrophysiology in different parts of the atrium, and the "normal" spatial d istribution of atrial refractoriness was reversed in patients,vith CAF, The electrophysiologic changes observed in patients with PAF appear to behave as if in transition from the control state to CAF, suggesting progressive c hanges in atrial electrophysiologic properties.