Atrial Fibrillation Spatiotemporal Complexity Is Affected by Pulmonary Vein Isolation

Introduction Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. However, it is still unclear how AF complexity observed on body surface is affected by this intervention. This study aims to evaluate whether PVI has an impact on AF complexity as measured through principal component analysis (PCA) of body surface potential maps (BSPMs). Methods BSPMs were acquired with a 252-lead vest in 22 persistent AF patients (20 male, 62 ± 11 years, maximum AF duration: 10± 18 months) before and after PVI. The atrial fibrillatory wave signal (9±6 $s$) was divided in $0.5-s$ segments, and AF complexity was assessed by the normalized amplitude norm dεand the cosine similarity $\cos(\alpha_{\epsilon})$ of the multilead error $\epsilon$ between the input signal at the frame $(s)$ and its PCA projection onto a 3D subspace computed in the previous segment $(s-1)$. AF organization was also quantified by the nondipolar component index (NDI), i.e., the amount of energy non-preserved by the 3D dipolar approximation of cardiac activity in the frame ($s$). Results A significant reduction in AF complexity was measured by all markers after PVI $(d_{\epsilon}$ and $\cos(\alpha_{\epsilon}):p < 0.01; NDI: p < 0.0001)$. Conclusions AF complexity can be reliably measured by the proposed BSPM features and reflect the impact of PVI.