Po-02-072 imageless electrocardiographic imaging for atrial electrophysiological characterization: a validation study

Abstract Background The mechanisms responsible for atrial fibrillation (AF) are not yet fully understood and treatment strategies remain suboptimal. Electrocardiographic imaging (ECGi) could provide new insights into the arrhythmogenic substrate’s characterization. Objective To validate a novel imageless ECGi technique against electroanatomical mapping (EAM) systems to evaluate its use in guiding therapeutic decisions. Methods Periprocedural ECGi was implemented on 12 patients submitted for pulmonary vein isolation with EAM arriving in sinus rhythm. As opposed to current methods requiring patient-specific torso-heart geometries from CT/MRI scans, the employed ECGi system computes a cardiac anatomical model from a 3D-camera torso reconstruction. Both ECGi signals and intracavitary recordings were acquired simultaneously during catheter stimulation from a single atrial site at two different pacing cycles and local activation time (LAT) maps were derived. As a result, an ECGi and an EAM map were obtained for both 300 and 600 ms distal coronary sinus pacing for each patient. These were then compared by splitting the left atrial geometries from both mapping methodologies into 7 predefined, clinically relevant regions and identifying the earliest and latest activation sites in each. Results For all 24 LAT maps under consideration, the pacing sites identified by non-invasive ECGi maps were consistent with those determined through EAM as 100% accuracy was obtained in terms of detecting the first activated region. As well as the correct stimulation area, according to the corresponding EAM instance, the earliest ECGi activations were also found in one of its immediate neighbours in 38% of the maps, indicating a broader region of interest. Regarding the latest activation sites, ECGi achieved an accurate localisation in 92% of the activation sequences and, similarly, other neighbouring regions showed the maximum LAT in one third of the studied maps. Conclusions Considering the spatial resolution constraints inherent to its non-invasive nature, imageless ECGi activation patterns are congruent with the gold-standard technique for substrate mapping without the need for prior medical imaging.