Non-invasive identification of deceleration zones in the atria using imageless ECGI: correlation with contact-mapping

Recent studies suggest that slow conduction velocity (CV) areas are associated with the perpetuation of AF and its recurrence after ablation. Electrocardiographic imaging (ECGI) provides beat-to-beat reconstruction of atrial electrical propagation non-invasively from body surface signals, offering real-time insights.

This study aims to validate non-invasive CV maps generated by a novel imageless ECGI technique against conventional electroanatomical mapping (EAM) systems to assess their potential for guiding therapeutic decisions.

ECGI was performed periprocedurally on eighteen persistent AF patients (61.1 ± 10.2 years; 29.2 ± 4.3 BMI; 17 male) undergoing pulmonary vein isolation with EAM, all presenting in sinus rhythm. Unlike standard ECGI requiring patient-specific torso-heart geometries from CT/MRI scans, this ECGI system uses a cardiac anatomical model derived from a 3D-camera torso reconstruction. Left atrial intracavitary and ECGI signals were recorded simultaneously during 600 ms distal coronary sinus catheter stimulation, allowing for the derivation and comparison of both invasive and non-invasive CV maps (Figure 1). The left atrium was segmented into seven predefined, clinically relevant regions with the mean CV and proportion of slow CV areas identified in each.

CV maps from both methodologies displayed similar central tendencies and variability (Figure 2). The global distribution of ECGI regional mean CV values closely aligned with those determined invasively through EAM, showing median values of 77.8 cm/s and 72.9 cm/s respectively. Interquartile ranges were also comparable (29.8 cm/s vs. 22.1 cm/s), with a minor trend toward faster velocities in ECGI. In terms of the location of potentially arrhythmogenic sites, regional slow CV area correlation was strongest in the atrial floor (0.92) and left atrial appendage (0.76).

Non-invasive atrial CV estimation via ECGI is consistent with EAM, the gold-standard technique for atrial tissue evaluation. This non-invasive electrical substrate characterization holds promise for both patient stratification in the outpatient clinic and for identifying ablation targets beyond pulmonary veins in the EP lab.

ECGI-EAM CV maps for a given patient