Carto 3 electroanatomical mapping system

As a standard, all patients underwent a preprocedural computed tomography angiography (CTA) scan of the left atrium and right atrium using a SOMATOM Definition Dual Source CT scanner (Siemens, Munich, Germany). The shortest longitudinal atrial diameters (L) and end-systolic atrial area were measured on two- (A1) and four-chamber (A2) views of the CTA images using the Carestream version 11 software (Phillips, Amsterdam, The Netherlands). LA volume and RA volume (LAV/RAV ml) were calculated according to the following area-length method based on the literature (8/3π x [(A1) x (A2)/L]) [14 (link)–16 (link)]. Afterwards, the indexed LAV and RAV (LAVI/RAVI, ml/m²) were calculated based on the body surface area (BSA) of each patient. In addition, atrial volumes were also determined by the CARTO^® 3 electroanatomical mapping system (Biosense Webster Inc., Diamond Bar, California, USA), based on the maps acquired by the fast anatomical mapping (FAM).

This was a multicenter, retrospective observational study of patients undergoing radiofrequency energy CA for focal AT in four tertiary-level electrophysiology Italian centers, using the CARTO3 electroanatomical mapping system (Biosense Webster, Diamond Bar, CA, USA) and a contact-force sensing catheter (Thermocool SmartTouch or Thermocool SmartTouch SF, Biosense Webster, Diamond Bar, CA, USA) equipped with an AI module. We included consecutive patients undergoing a first-time procedure, as well as patients with previous catheter ablation for supraventricular arrhythmias, but only if the index focal AT originated from a site not previously ablated. Each procedure performed between 2017 and 2021 was retrospectively reviewed, and a minimum follow-up of six months was required for inclusion in the analysis. The research reported in this paper adhered to institutional standards, national legal requirements, and the Helsinki Declaration as revised in 2013. Every patient provided his/her written informed consent.

All patients underwent a preprocedural cardiac computed tomography (CT) scan within 12 hours before the procedure for evaluating abnormal intracariac structure, thrombus, or coronary artery stenosis. All patients in our series were planned to undergo an ablation procedure with the fluoroless approach. Nevertheless, a fluoroscopy system was prepared for its immediate use when needed. An electrophysiology laboratory system fully equipped with the CARTO® 3 electroanatomical mapping system (Biosense‐Webster, Diamond Bar, CA, USA), with the Confidence® module for CARTOSOUND®, CARTO VISITAG®, and CARTO VISITAG® with Ablation Index, was used.