Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Mapping & Imaging D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-167 - Potential Mechanism Of The Existence Of Low Voltage Areas In The Anterior Left Atrium In Patients With Atrial Fibrillation (ID 477)


Background: Atrial fibrillation (AF) patients sometimes have low voltage areas in the anterior left atrium (aLA-LVAs), which can be an arrhythmogenic substrate. LVAs have been reported to be formed by remodeling of the left atrium, but there have been few reports about the association between the LVA formation and extracardiac structures.
Methods: In 101 patients (77 males, mean age 64.0±10.2 year, 53 persistent AF patients) who underwent atrial fibrillation (AF) ablation, we investigated the relationship between the aLA-LVAs identified on pre-ablation voltage LA maps (Figure 1) and the 3D CT image-derived parameters (Figure 2): angles between the ascending aorta and LA (Ao-LA angle) and between the ascending aorta and left ventricle (Ao-LV angle), and the coronary cusp diameter.
Results: The proportion of women among the patients with aLA-LVAs was higher than among those without (38% vs. 19%). In 29 (29%) patients with aLA-LVAs, the Ao-LA angle was significantly lower (20.8±1.3° vs. 25.0±0.8°), Ao-LV angle higher (130.9±1.5° vs. 126.1±1.0°), NCC larger (20.5±0.5mm vs. 19.3±0.3mm), and closer to the LA anterior wall (2.33±0.14mm vs. 2.75±0.09mm) than in those without, but was not related to the RCC, LCC, or LA diameter. In all patients, the NCC was in contact with the LA anterior, and overlapped with the aLA-LVAs region on 3D mapping. Patients with lower BWs tended to have larger aLA-LVAs (p<0.05 for all).
Conclusion: The aLA-LVAs are more common in lower BW women, with ascending aortas that have a large NCC running close to the LA. This suggests that there is compression from the NCC and ascending aorta because the change in the physique may be involved in the creation of the aLA-LVAs.