Background: Areas with high frequency activity within the atrium are thought to be\nââ?¬Ë?driversââ?¬â?¢ of the rhythm in patients with atrial fibrillation (AF) and ablation of these areas\nseems to be an effective therapy in eliminating DF gradient and restoring sinus rhythm.\nClinical groups have applied the traditional FFT-based approach to generate the threedimensional\ndominant frequency (3D DF) maps during electrophysiology (EP) procedures\nbut literature is restricted on using alternative spectral estimation techniques\nthat can have a better frequency resolution that FFT-based spectral estimation.\nMethods: Autoregressive (AR) model-based spectral estimation techniques, with\nemphasis on selection of appropriate sampling rate and AR model order, were implemented\nto generate high-density 3D DF maps of atrial electrograms (AEGs) in persistent\natrial fibrillation (persAF). For each patient, 2048 simultaneous AEGs were recorded\nfor 20.478 s-long segments in the left atrium (LA) and exported for analysis, together\nwith their anatomical locations. After the DFs were identified using AR-based spectral\nestimation, they were colour coded to produce sequential 3D DF maps. These maps\nwere systematically compared with maps found using the Fourier-based approach.\nResults: 3D DF maps can be obtained using AR-based spectral estimation after AEGs\ndownsampling (DS) and the resulting maps are very similar to those obtained using\nFFT-based spectral estimation (mean 90.23 %). There were no significant differences\nbetween AR techniques (p = 0.62). The processing time for AR-based approach was\nconsiderably shorter (from 5.44 to 5.05 s) when lower sampling frequencies and model\norder values were used. Higher levels of DS presented higher rates of DF agreement\n(sampling frequency of 37.5 Hz).\nConclusion: We have demonstrated the feasibility of using AR spectral estimation\nmethods for producing 3D DF maps and characterised their differences to the maps\nproduced using the FFT technique, offering an alternative approach for 3D DF computation\nin human persAF studies.
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