Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Experimental methods D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-154 - Renewal Rate Constants Of Phase Singularity Formation And Destruction In Atrial Fibrillation Are Temporally Stable: Implications For Af Mechanism (ID 1211)

Abstract

Background: A stable, robust and easily measurable marker of underlying AF dynamics might be helpful in developing novel mechanism-based approaches for AF ablation. We hypothesized that renewal rate constants λf and λd, previously shown to quantify rates of phase singularity (PS) formation and destruction during fibrillation, could be used as such a marker.
Objective: We hypothesised that λfd are temporally stable and can be used as robust markers of underlying fibrillatory dynamics.
Methods: Basket recordings of AF from 20 patients (43 epochs) and 12 sheep (20 epochs) were studied. Temporal stability of λf/λd was analyzed by investigating if averages created using 20 second windows have (i) a stable mean, ii) time-independent autocorrelation functions, and iii) coefficient of variations (CVs) of λf/λd over time lower than for established AF-dynamic measures (dominant frequency (DF) and AF cycle length (AFCL)).
Results: Mean λfd estimated from 20-sec windows was constant (R2λf=0.97; R2λd=0.99), with time-invariant autocorrelation functions. CV was also lower for λf (3.7% (95%CI,1.6,5.9)) and λd (2.6% (1.5,3.8)) versus DF (16.3% (95%CI,2.5,30)) and AFCL (12.2% (95%CI,6.7,17.7)). CV of λf and λd was also significantly different to DF (Pλf < 0.001; Pλd < 0.001) and AFCL (Pλf < 0.001; Pλd < 0.001).
Conclusion: λf/λd, which precisely define the rates of formation and destruction of AF-maintaining rotors, are temporally stable, providing a robust and clinically usable mechanistic tool to directly quantify AF dynamics, mechanistically connected to the rotor regeneration that determines AF perpetuation.
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