Background: The novel CARTOFINDER module allows for a simultaneous and automated detection of repetitive focal and rotational activations during electroanatomical mapping using a multi-electrode catheter in patients with atrial arrhythmias.  

Aim: This study aimed to validate the CARTOFINDER algorithm for the detection of potential drivers for atrial fibrillation (AF) in a routine ablation workflow and to access the effects of AF ablation on regions of interests (ROI) from CARTOFINDER-guided mapping.

Methods: Forty-four consecutive patients underwent AF ablation for persistent AF using a 3D-mapping system with the novel integrated CARTOFINDER module (Carto System®, Biosense Webster Inc.). All patients presented with persistent AF and mapping was performed using a multi-electrode catheter (PentaRay, Biosense-Webster Inc.). The ablation workflow was divided into the following steps: 1. 3D reconstruction of the right (RA) and left atrium (LA). 2. Identification of the individual ROIs separated for focal and rotational activity in the RA and LA. 3. Ablation index guided pulmonary vein isolation (PVI). 4. Repeat mapping for ROIs in the RA and LA. 5. Direct current electrical cardioversion. 6. Confirmation of persistent PVI and bipolar ultra-high density mapping of the RA and LA followed by substrate modification if there was evidence for local bipolar low-voltage in the LA.

Results: Acute PVI was achieved in all patients (100%). In 28% of these patients additional substrate modification in the LA was performed. AF termination was observed in 4 patients. Mean procedure duration (skin-to-skin) was 137±30 min, mapping time for ROIs in the RA was 8±5 min and 11±5 for the LA, respectively. A mean number of 149±82 ROIs were revealed from CARTOFINDER. In the LA, focal activity was predominantly observed inside the LA appendage (LAA) and in close relationship to the pulmonary vein ostia. The majority of rotational activities was found along the mitral valve annulus. In the RA, the majority of ROIs was found at the septum and in close relationship to the RA appendage. The mean amount of bipolar low voltage was 20±11 for the RA and 32±11 for the LA. During re-mapping for ROIs after AF ablation (duration between 1^st and 2^nd CARTOFINDER mapping: 90±40min) we observed the elimination of ROIs close to the linear ablation set for PVI. In addition, rotational activity could not be re-identified at repeat mapping. We found persisted focal activity in the LAA and RA after AF ablation (p<0.05).  

Conclusions: This is the first study reporting data from the novel CARTOFINDER algorithm under routine clinical conditions in an ablation workflow for persistent AF. ROIs could be discriminated and visualized in all patients. These ROIs might potentially be an additional and individual ablation target when we are able to understand the underlying arrhythmia substrate.