Fig. 3: Time-course of atrial electromechanical remodeling during atrial fibrillation progression in pigs.

a Schematic experimental flow-chart. b Comparisons of left atrial (LA) areas between atrial fibrillation (AF) animals and sham-operated controls over the follow-up. c, d Sample lead II-derived atrial ECG tracings and their simultaneous TDI-derived signals taken at 6 (c) and 15 (d) weeks (w) after the first recorded episode lasting ≥6 s (t0). Their respective power spectral density and DF peaks are also shown. Light red tracings show the original signals before processing. e Time-course of electromechanical remodeling during AF progression in the pig model. Dashed lines show time-course trends for each parameter. At the beginning of AF history (t0), DF values of TDI signals from atrial sampling regions were occasionally higher than DF values from lead II, reflecting the more global nature of atrial surface activations on lead II. f DF analysis of lead II-derived atrial ECG signals at different time-points during the study protocol. Box-plots show median and interquartile range. g 92% of pigs showed EMD by the time electrical remodeling reached a plateau phase between week 21 and 27 (gray vertical bar). Deviation intervals in b and e represent standard errors of mean values. Two-sided unpaired/paired Student’s t tests were used to assess differences in (e) and (f), respectively. Source data are provided as a Source Data file. PM pacemaker. AVN, DF, EMD and TDI as in Fig. 1.