Catheter configuration for mapping micro-anatomic reentries sustaining atrial fibrillation: A simulation study

Figures

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  Fig 1. Simulation of micro-anatomical reentry. (A) Local activation time (LAT) map. (B) Transmembrane potential during initial atrial activation. (C) Transmembrane potential during micro-anatomical reentry activation. (D) Electrogram (EGM) traces (blue) recorded from electrodes positioned 0, 3, and 6 mm from the micro-anatomical reentry (panel A), compared with transmembrane potentials (black) from their closest points on the micro-anatomical reentry (AP #1) and atrial wall (AP #3). (E) Detailed amplitude estimation for wall and track activations.

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  Fig 2. Unipolar EGM mapping of micro-anatomical reentry. Left panels illustrate the schematic EGM positions relative to the reentrant structure for each inter-electrode spacing (1, 3, 6, and 9 mm). Middle and right panels display the recorded reentry track-to-wall ratio and LAT maps, respectively, for each inter-electrode spacing (1, 3, 6, and 9 mm) and two EGM distances to the atrial wall (0.25 mm and 1 mm). Magenta rectangles on LAT maps represent the reentrant path identified, with the highest coverage of the cycle length.

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  Fig 3. Bipolar mapping of micro-anatomical reentry with close EGM-to-Atria contact. Left and Right panels illustrate the schematic EGM positions relative to the reentrant structure and LAT maps, respectively, for each inter-electrode spacing (1, 3, 6, and 9 mm) and two bipolar orientations (0º and 90º, columns) with an EGM-to-atrial wall contact distance of 0.25 mm. Magenta rectangles on LAT maps represent the reentrant path identified, with the highest coverage of the cycle length.

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  Fig 4. Bipolar mapping of micro-anatomical reentry with poor EGM-to-Atria contact. Left and Right panels illustrate the schematic EGM positions relative to the reentrant structure and LAT maps, respectively, for each inter-electrode spacing (1, 3, 6, and 9 mm) and two bipolar orientations (0º and 90º) with an EGM-to-atrial wall contact distance of 1 mm. Magenta rectangles on LAT maps represent the reentrant path identified, with the highest coverage of the cycle length.

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  Fig 5. Omnipolar mapping of micro-anatomical reentry. Left and Right panels illustrate the schematic EGM positions relative to the reentrant structure and LAT maps, respectively, for each inter-electrode spacing (1, 3, 6, and 9 mm) and two EGM distances to the atrial wall (0.25 mm and 1 mm, columns). Magenta rectangles on LAT maps represent the reentrant path identified, with the highest coverage of the cycle length.

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  Fig 6. Percentage of cases identifying the micro-reentry based on EGMs catheter position and configuration. A) Unipolar mapping. B) Omnipolar mapping. C) Bipolar mapping oriented along with the micro-reentrant path. D) Bipolar mapping oriented 90º with respect to the micro-reentrant path. E) Combination of unipolar and omnipolar mapping.

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  Fig 7. Micro-reentry detection under different substrate conditions. A) Baseline substrate. B) Micro-reentrant track with reduced thickness to 50% respect to baseline. C) Micro-reentrant track with reduced width to 50% respect to baseline. D) Micro-reentrant track with increased diffusion, so atrial wall and micro-reentrant track conduction velocity are similar.

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  Fig 8. Mapping considerations for micro-reentry identification. A) Effect of threshold used for automatically considering a reentry, expressed as percentage of the cycle length, on the percentage of cases in which the micro-reentry was identifiable. Examples of micro-reentrant path identification on omnipolar mapping, for (B) 1 mm resolution and for (C) 3 mm resolution: top-left panel shows the omnipolar LAT map and the automatically-detected reentry (purple line); top-right panel shows the LAT sequence on the detected reentrant path (purple) and its first derivative (brown); bottom-left panel shows the propagation direction detected by omnipolar mapping (black arrows); bottom-right panel shows the conduction velocity map obtained with omnipolar mapping.