An improved window of interest for electroanatomical mapping of atrial tachycardia

Alexis Mechulan,Pierre Dieuzaide,Sok-Sithikun Bun,Alexandre Masse,Angélique Peret,Frederic Pons,Sébastien Prévot,Ahmed Bouharaoua,Lauriane Leong-Feng

doi:10.1007/s10840-021-00940-0

Abstract

PurposeDiagnosis of atrial tachycardia (AT) with 3D mapping system remains challenging due to fibrosis or previous ablation. This study aims to evaluate a new electroanatomical mapping annotation setting using a window of interest adjusted at the end of the P wave (WOIp wave) to identify the AT mechanism more accurately.MethodsTwenty patients with successful ablation of left AT using navigation system CARTO3 were evaluated. Two maps for each patient were generated offline using either conventional settings of WOI (WOIconv.) or WOIp wave. Three investigators from two centres analysed the maps blindly.ResultsMechanisms of AT were macroreentrant in 14/20 patients (70%) and focal in 6/20 (30%). WOIp wave resulted in a significant increase in the percentage of correct identification of the mechanism based on mapping alone (93.3 ± 13.7% vs 58.3 ± 33.9%; p = 0.0003) compared with WOIconv.. Diagnoses based on mapping were arrived at faster (27.8 ± 16.4 s vs 38.97 ± 13.64 s, respectively; p = 0.0231) and with a greater confidence in the diagnosis (confidence index 2.57 ± 0.45 vs 2.12 ± 0.45, respectively; p = 0.0024). With perimitral re-entry specifically “early meets late” was closer to the anatomical region of the mitral isthmus (15.9 ± 20.9 mm vs 48.77 ± 23.23 mm, respectively; p = 0.0028).ConclusionsThis study found that electroanatomical mapping acquisition with a window of interest set at the end of the P wave improves the ability to diagnose the arrhythmia mechanism based on the initial map. It is particularly beneficial in identifying area of interest for ablation in perimitral AT.

Highlights

Interpretation of activation mapping to determine the mechanism of atrial tachycardia (AT) may be challenging because of the presence of intrinsic scarring further complicated by previous ablation or fibrosis [1, 2]
In typical atrial flutter, the plateau phase of slow conduction following the P wave corresponds to the region of a critical isthmus in macroreentrant AT [5]
The study population included a total of 40 maps in 20 patients who presented for first-time AT ablation (n = 2) or redo atrial arrhythmia ablation (n = 18) because of organized AT

Summary

Introduction

Interpretation of activation mapping to determine the mechanism of atrial tachycardia (AT) may be challenging because of the presence of intrinsic scarring further complicated by previous ablation or fibrosis [1, 2]. J Interv Card Electrophysiol (WOIp wave) improves the ability to diagnose the arrhythmia mechanism based on the initial mapping. Positioning the WOI at the end of the P wave prior to a relatively isoelectric component should be related to the entrance into the slow conduction and improve the ability to identify the critical slow conduction zone on the map. Focal AT is generally less problematic, but the P wave onset should reflect anatomical exit from the focus from which it spreads centrifugally [6]. This technique is feasible if there is an identifiable relatively isoelectric interval which there appears to be most of the time

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Conclusion