To assess the accuracy and clinical utility of a novel non-invasive ECGI mapping system in identifying arrhythmogenic regions of interest in patients with congenital heart disease.

Congenital heart disease (CHD) survivors often present with complex anatomical remodeling and progressive atrial or ventricular arrhythmias that significantly impact their quality of life and long-term prognosis. Traditional diagnostic tools, such as the standard 12-lead ECG, frequently fall short in these patients due to displaced cardiac structures and atypical conduction pathways. While invasive electroanatomical mapping remains the gold standard for arrhythmia characterization, there is a critical clinical need for non-invasive, high-resolution tools that can streamline procedural planning and improve the precision of therapeutic interventions like catheter ablation or cardiac resynchronization therapy (CRT).

This single-center, prospective pilot study investigates the clinical utility and accuracy of a novel Electrocardiographic Imaging (ECGI) system. This system aims to overcome the limitations of conventional mapping by offering real-time, non-invasive 3D reconstruction of cardiac electrical activity. A key innovation of this technology is its ability to utilize statistical estimation algorithms to generate cardiac geometries, potentially bypassing the need for time-consuming medical image segmentation (CT/MRI) in standard cases, while allowing for personalized anatomical integration in complex congenital presentations.

Study Workflow

After obtaining informed consent, participants scheduled for elective electrophysiological (EP) studies or device implantations will follow a multi-modal diagnostic protocol:

1. Body Surface Mapping: Placement of the 128-electrode vest and 3D torso reconstruction to localize electrode positions relative to the heart.
2. Standard 12-Lead ECG Acquisition: Traditional recordings are captured to serve as a baseline for head-to-head accuracy comparisons.
3. Intraoperative Invasive Mapping: During the clinical procedure, high-density endocardial mapping is performed using standard-of-care electroanatomical mapping systems to provide the definitive "ground truth" for arrhythmia localization.
4. Anatomical Imaging Integration: Review of existing CT or MRI data (or acquisition based on clinical indication) to perform personalized segmentation.
5. Comparative Analysis: A blinded expert review will compare the localization of "regions of interest" (ROI) between the ECGI system, the 12-lead ECG, and the invasive endocardial maps.

Patient Profile The trial focuses exclusively on patients with congenital heart disease, a cohort currently underrepresented in non-invasive mapping research. Eligible participants include those undergoing EP studies for tachycardia or those requiring device therapy (pacemakers/CRT) where optimal lead placement is critical.

Safety and Risk Mitigation The ECGI mapping process is entirely non-invasive and adds no procedural risk to the patient. No additional invasive maneuvers are required beyond what is already clinically indicated for the patient's standard care.

Inclusion Criteria:

• Patients with congenital pathologies and a clinical indication for an invasive electroanatomical study and/or implantation of intracavitary stimulation devices.
• Written informed consent form signed to participate in the study.
• Ability to stand upright to allow for the 3D torso reconstruction required by the ECGI system.

Exclusion Criteria:

• Patients under 18 years of age.
• Inability to undergo endocardial catheterization (e.g., pregnant or breastfeeding women).
• Physical or mental incapacity to understand and accept the informed consent.

Adult patients (≥18 years) diagnosed with congenital heart disease (simple, moderate, or complex congenital heart defects ranging from atrial septal defects to complex single-ventricle anatomies such as Fontan circulation) who are referred to the Electrophysiology Unit or Cardiology Department for clinical management of arrhythmias. Eligible patients will be invited to participate during their pre-procedural consultation or upon admission for their scheduled intervention.

Specifically, participants will be selected from the following clinical streams: (1) Catheter ablation candidates presenting with symptomatic tachyarrhythmias (atrial or ventricular) that have a clinical indication for an invasive electroanatomical mapping and ablation procedure (2) Device implantation candidates referred for the implantation or upgrade of intracavitary stimulation devices, including permanent pacemakers, ICDs or CRT. The recruitment process aims to capture a representative spectrum of CHD complexity,