Assessing the atrial substrate: electrograms from the coronary sinus can predict left atrial fibrosis

Abstract Background Left atrial fibrosis plays a key role regarding the success rate of pulmonary vein isolation for atrial fibrillation. It can be analyzed using LGE-MRI or invasive LA electroanatomical mapping. Assessing LA substrate prior to performing LA ablation procedures might help in optimizing the ablation approach. Method We analysed highdensity-electroanatomical maps of the left atrium derived by Carto 3 from 282 consecutive atrial fibrillation patients scheduled for RF pulmonary vein isolation (PVI). Maps were divided into 5 different anatomical areas and fibrosis was defined as local voltage 5%) was present in 54% of the patients with the maximum incidence of 100% at the anterior and 80% at the posterior wall. Signal amplituds in the proximal CS position significantly correlated with presence of LA fibrosis in the posterior LA (R 0.84, p