From signal analysis to clinical practice: the use of peak frequency in mapping and ablation

Figures

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  Figure 1. Methodology used for PF analysis and the difference to DF. (A) PF trace that reflects a measure of the highest signal frequencies detected in the intracardiac EGMs as a function of time. From the PF trace, 2 measures are obtained and assigned to each EGM point (1): PF timing (green line), which is derived from the time of the highest detected frequency peak. (2) PF magnitude (red line), which represents the highest frequency detected in the EGM. (B) Difference between PF and DF. It shows an EGM and its corresponding fast Fourier transform. The DF range (dashed orange box) represents the frequency of highest energy (typically low frequency), whereas the PF range (dashed red box) represents the highest frequencies in the EGM, often of low energy. Reproduced from [S. Al-Aidarous et al.], under the terms of the Creative Commons Attribution–Non-Commercial License (6).

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  Figure 2. Electro-anatomical voltage map depicting the following: (A) case of LA MRAT spinning around the left PVs in between LAA and the veins, in a patient who had undergone previous PVI. PF window adjusted to highlight a confined area of the highest relative frequency within the scar (set in this example to >500 Hz). (B) Signals of the HD-Grid catheter depict the complex fractionated and high-frequency signals. Yellow lines on the HD-Grid tracings (blue) indicate the PF component of each signal, to which the OTNF algorithm annotated to create the map. (C) Arrhythmia terminated with the first ablation lesion (red dot) targeted precisely at the area of highest frequency. A few additional consolidation lesions were applied subsequently, and the arrhythmia was non-inducible afterward. Reproduced from [Adrian M. Petzl et al.], with direct permission from the author (21).

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  Figure 3. Delta F–P parameter for predicting successful idiopathic outflow tract VA elimination by a single ablation application. Reproduced from [T. Nishimura et al.], under the terms of the Creative Commons Attribution–Non-Commercial License (25).

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  Figure 4. Emphasis maps pre- and post-ablation for a patient with ICM and scar related VT. SR substrate map with PF ≥ 200 Hz was emphasised. All ablation lesions were within 5 mm of the low voltage-high PF region. Post-ablation re-map shows a near complete elimination of low-voltage–high-PF region. Reproduced from [J. Mayer et al.], with direct permission from the author (3).

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  Figure 5. Late activation and PF maps for a patient with typical AVNRT. PF maps were computed online prior ablation and displayed on the activation map with shadowed areas where PF was <200 Hz (figure, left panel). Focal radiofrequency application (was directed successfully to the areas of late activation (left panel) and low frequency (right panel) Reproduced from [A. Handayani et al.], under the terms of the Creative Commons Attribution–Non-Commercial License (32).