A novel approach for localizing non-pulmonary vein triggers: atrial pace mapping with automatic intracardiac pattern matching

Abstract Background and Aims Atrial pace mapping (APM) is a tool for localizing the origin of non-sustained atrial tachycardia (nsAT), or atrial fibrillation (AF) triggers, commonly not amenable to activation mapping. However, the conventional approach's success is limited. We propose a novel approach for APM using an automatic ECG pattern-matching algorithm with intracardiac unipolar signals (aICPM). Ref. Methods A total of 44 out of 72 (61.1%) patients who underwent a redo ablation procedure for recurrence of AF with absence of low-voltage substrate were included prospectively. APM with aICPM was performed with six biatrial unipolar signals to create score maps (Figure 1, Figure 2). Ablation targeted sites with the best IC pattern similarity. The primary endpoint was non-inducibility, and the secondary was freedom from AF/AT during a short-term follow-up. Results Twenty-six reproducible nonPV-triggers were reproducibly induced in 24 patients. The median age was 69.5 (IQR 62.3; 77.5), and eight patients (37.5%) were female. Seven patients (29.2%) had a persistent form of AF. The left atrial (LA) diameter was 43 (41; 44.8) mm, and the left ventricular ejection fraction was 55 (55; 60) %. APM with aICPM identified distinct areas of the best IC pattern similarity (median of 81%; median top 10% IC pattern matching area: 0.5 cm²) in all 24 patients. The median time to create a score map was 4.7 (IQR 3.3; 6.3) minutes, with 100 (IQR 77; 153) points per map. Radiofrequency ablation was successfully performed in 22 of 24 patients (median ablation time of 139 (IQR 82; 182) seconds and an ablation area of 2.0 (IQR 1.1; 2.3) cm²). Two patients received ethanol ablation of the vein of Marshall. After ablation, non-PV triggers were non-inducible in all cases. Within 5.9±1.87 months of follow-up, 5 (20.8%) patients experienced AF recurrence. Conclusion The novel approach rapidly and precisely localizes non-PV triggers by generating detailed atrial pacemaps using intracardiac signals with the automatic ECG pattern-matching algorithm.Figure 1.Atrial pace mapping Figure 2.IC unipolar signals