Left atrial model reconstruction in atrial fibrillation ablation: reliability of new mapping and complex impedance systems

Aims The effectiveness of atrial fibrillation (AF) ablation relies on detailed knowledge of the anatomy of the left atrium (LA) and pulmonary veins (PVs). It is common to combine computed tomography/magnetic resonance (CT/MR) with imaging by electroanatomical (EA) mapping systems. The aim of this study was to evaluate the accuracy of LA anatomical reconstruction by 'One Model' and 'VeriSense' tools (Ensite Velocity 3.0, St Jude Medical), compared with CT/MR imaging. Methods and results Seventy-two patients with AF underwent pre-procedural imaging (97% CT-scan, 3% MR imaging) and transcatheter ablation of PVs. Operators were blinded to CT/MR imaging. Electrical Coupling Index (ECI) was used to recognize venous structures when the circular catheter could not. The LA 'One Model' map was obtained without complications; all 124 main left PVs and 144 main right PVs were detected. Nine of 9 intermediate right PVs and 30 of 30 early branches were detected, whereas 1 of the 27 early branches on the right inferior PVs was missed. Comparison between LA intervein distances measured on the roof (RO) and the posterior wall (PW) showed a high correspondence between the EA model and CT/MR imaging (RO CT/MR imaging vs. EA: 32 ± 7 vs. 32 ± 7 mm; PW CT/MR imaging vs. EA: 36 ± 6 vs. 36 ± 7 mm). The EA model yielded slightly larger PV ostia diameters, owing to the distortion caused by catheter pressure. Conclusions Recent 3D mapping tools allow outstanding anatomical rendering and are key in complex ablation procedure set-up. This study shows that 3D anatomical reconstruction of LA, PVs, and their variable branches is not only safe and fast but also accurate and reliable.