Find Me If You Can: First Clinical Experience Using the Novel CARTOFINDER Algorithm in a Routine Workflow for Atrial Fibrillation Ablation

Abstract

Aims: The CARTOFINDER module allows for simultaneous and automated detection of repetitive focal and rotational activations in patients with atrial arrhythmias. This study aimed to validate the CARTOFINDER algorithm for the detection of potential drivers for atrial fibrillation (AF) and to access their potential impact on individual arrhythmia substrates.

Methods: Fifty consecutive patients underwent AF ablation for persistent AF (PERS), using a 3D-mapping system with the integrated CARTOFINDER module. Regions of interest (ROIs) were identified before and after ablation, and their spatial and temporal relationship was correlated with areas of fibrosis.

Results: Procedural success was achieved in all patients and 42% received ablation beyond pulmonary vein isolation (PVI). AF termination was observed in 6 patients (12%). The mean procedure duration was 134 ± 29 min. ROIs were revealed in all patients (mean n = 77 ± 52) and there was no statistical evidence for a predilection site. There was no significant anatomical correlation between ROIs and bipolar low voltage. Remapping confirmed the elimination of ROIs in relation to the individual ablation site, a limited reproducibility of rotational ROIs and persistent focal activity over time in some anatomical segments. ROIs were not a predictor for AF recurrence during following ablation.

Conclusions: CARTOFINDER mapping can be integrated into a routine workflow for AF ablation. ROIs could be discriminated in all patients and an ablation effect was observed in some patients, whereas persistent activity was found in certain anatomical segments, even after ablation. ROIs might be an additional ablation target when we are able to understand the individual substrate.

Keywords: CARTOFINDER; atrial fibrillation; catheter ablation; panoramic mapping.

Figure 1

Representative example of our CARTOFINDER workflow (focal activity, green color; rotational activity, blue color) in patients with persistent atrial fibrillation (AF, atrial fibrillation; PVI, pulmonary vein isolation; SR, sinus rhythm). The mean time for each workflow-step is visualized in minutes ± standard deviation.

Figure 2

CARTOFINDER-guided mapping for regions of interest (ROI) was conducted automatically, utilizing the multipolar PentaRay catheter. (A) Photographic representation of the PentaRay catheter with its five splines. (B) Representative example for CARTOFINDER-guided mapping for ROIs at the posterior left atrial wall, using the PentaRay mapping catheter. (C) Bipolar high-density mapping of the left atrium (B,C) posterior–anterior view.

Figure 3

(A) Schematic reconstruction from of the right (RA) and left atrium (LA) in anterior/posterior (AP) and posterior/anterior (PA) view. The RA was divided into the following segments: right atrial appendage (RA RAA), coronary sinus ostial area (RA CS), superior lateral (RA SUP LAT), inferior lateral (RA INF LAT), superior septal (RA SUP SEP), inferior septal (RA INF SEP), superior cava vein (SCV), and inferior cava vein (ICV). The LA was divided into the following segments: superior (LA SUP), posterior (LA POST), anterior (LA ANT), inferior (LA INF), lateral (LA LAT), right superior pulmonary vein (LA RSPV), right inferior PV (LA RIPV), left superior PV (LA LSPV), left inferior PV (LA IPV), septal-anterior (LA SEPT ANT), and left atrial appendage (LAA). (B) Distribution of Regions of Interest (ROI; red color, focal + rotational; green color, focal; blue color, rotational) from CARTOFINDER mapping separated per atrial segment.

Figure 4

(A,C) Typical example for focal activities (green color) revealed from CARTOFINDER mapping of the right and left atrium and left atrial appendage. (D) The grey ring represents the center of a mapping position, using the PentaRay catheter. The light grey surface around the ring visualizes the coverage of the LA wall surface with the five PentaRay splines. (B) Focal activation is detected by identifying an S wave in the unipolar electrograms. If S wave patterns preceding activity on neighboring electrodes are detected during at least two consecutive atrial cycles, the site is designated as a focal source.

Figure 5

(A,C,D) Typical example for rotational activities (blue color) revealed from CARTOFINDER mapping of the left atrium. (B) Rotational activation is detected by identifying pan-systolic activation occurring in consecutive electrodes. A pan-systolic activation wave is defined as a series of electrograms in consecutive electrodes, occupying more than 50% of the local cycle length with a distance of less than 20 mm between the starting and ending points of the wave. Two or more such pan-systolic activations occurring are defined as a rotational activation.

Figure 6

Representative image to demonstrate and the temporal stability of region of interests (ROIs) from CARTOFINDER mapping. Upper panels: Findings from CARTOFINDER mapping prior to ablation. Lower panels: Findings from CARTOFINDER mapping after ablation. (A,C,D,F) Persistent focal activity (green spots) in the left atrial appendage, independent of pulmonary vein isolation and left atrial substrate modification. (A,D) In contrast, the rotational activity (blue spots) disappeared after catheter ablation. (B,E) This was also the case for focal activity (green spots) around the left sided pulmonary veins.