Peak frequency can be effectively used to characterize scar in atrial fibrillation

Figures

• 

  Figure 1. Study methodology diagram. AF = atrial fibrillation; DCCV = direct current cardioversion; PI = pacing interval; SR = sinus rhythm.

• 

  Figure 2. Methodology used for peak frequency (PF) analysis and the difference to the dominant frequency (DF). A: PF trace that reflects a measure of the highest signal frequencies detected in the intracardiac electrograms (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 (FFT). 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.

• 

  Figure 3. Voltage maps and peak frequency (PF) maps re-created in MatLab. A: Omnipolar voltage (OV) map created in atrial fibrillation (AF) in an anterior-posterior view. B: Bipolar voltage (BV) map created in sinus rhythm (SR) with atrial pacing at a pacing interval (PI) of 600 ms in an anterior-posterior view. C: BV map created in SR with atrial pacing at a PI of 250 ms in an anterior-posterior view. Low voltage zones (LVZs) are shown in red, and non–low voltage zones (nLVZs) are shown in green. D: PF map in an anterior-posterior view, created from PF measurements obtained in AF. When comparing the maps, the OV map in AF resembles the BV map in SR at a PI of 250 ms and both these maps demonstrate additional LVZs not seen on the BV map in SR at a PI of 600 ms, particularly anterior to the right lower pulmonary vein and anterior to the left atrial appendage. These additional LVZs represented sites of functional remodeling. LVZs seen across all the 3 maps represent sites of fixed remodeling. The PF map can effectively identify sites of fixed remodeling (PF ≤214 Hz represented in red) and functional remodeling (PF 215–236 Hz represented in blue). The OV map in AF demonstrated additional LVZs…

• 

  Figure 4. Voltage maps and peak frequency (PF) maps re-created in MatLab. A: Omnipolar voltage (OV) map created in atrial fibrillation (AF) in a posterior-anterior view. B: Bipolar voltage (BV) map created in sinus rhythm (SR) with atrial pacing at a pacing interval (PI) of 600 ms in a posterior-anterior view. C: BV map created in SR with atrial pacing at a PI of 250 ms in a posterior-anterior view. Low voltage zones (LVZs) are shown in red, and non–low voltage zones (nLVZs) are shown in green. D: PF map in a posterior-anterior view, created from PF measurements obtained in AF. When comparing the maps, the OV map in AF resembles the BV map in SR at a PI of 250 ms and both these maps demonstrate additional LVZs not seen on the BV map in SR at a PI of 600 ms, particularly posterior to the left lower pulmonary vein and posterior to the right upper pulmonary veins. These additional LVZs thereby represented sites of functional remodeling. LVZs seen across all the 3 maps represented sites of fixed remodeling. The PF map can effectively identify sites of fixed remodeling (PF ≤214 Hz represented in red) and functional remodeling (PF 215–236 Hz represented in blue). The OV map in AF demonstrated…

• 

  Figure 5. Voltage maps and peak frequency (PF) maps re-created in MatLab. A: Omnipolar voltage (OV) map created in atrial fibrillation (AF) in a posterior-anterior view. B: Bipolar voltage (BV) map created in sinus rhythm (SR) with atrial pacing at a pacing interval (PI) of 600 ms in a posterior-anterior view. C: BV map created in SR with atrial pacing at a PI of 250 ms in a posterior-anterior view. Low voltage zones (LVZs) are shown in red, and non–low voltage zones (nLVZs) are shown in green. D: PF map in a posterior-anterior view, created from PF measurements obtained in AF. When comparing the maps, the OV map in AF resembles the BV map in SR at a PI of 250 ms and both these maps demonstrate additional LVZs not seen on the BV map in SR at a PI of 600 ms, particularly the mid posterior wall. These additional LVZs thereby represented sites of functional remodeling. LVZs seen across all the 3 maps represented sites of fixed remodeling. The PF map can effectively identify sites of fixed remodeling (PF ≤214 Hz represented in red) and functional remodeling (PF 215–236 Hz represented in blue). The OV map in AF demonstrated additional LVZs that were not seen on either of the SR maps. These…

• 

  Supplemental Figure 1.

• 

  Supplemental Figure 2.