Relationship Between Fibrosis Detected on?Late?Gadolinium-Enhanced Cardiac?Magnetic Resonance and Re-Entrant?Activity Assessed With?Electrocardiographic Imaging in?Human?Persistent Atrial Fibrillation

摘要

ObjectivesThis study sought to assess the relationship between fibrosis and re-entrant activity in persistent atrial?fibrillation (AF).BackgroundThe mechanisms involved in sustaining re-entrant activity during AF are poorly understood.MethodsForty-one patients with persistent AF (age 56 ± 12 years; 6 women) were evaluated. High-resolution electrocardiographic imaging (ECGI) was performed during AF by using a 252-chest electrode array, and phase mapping was applied to locate re-entrant activity. Sites of high re-entrant activity were defined as re-entrant regions. Late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) was performed at 1.25?× 1.25?× 2.5 mm resolution to characterize atrial fibrosis and measure atrial volumes. The relationship between LGE burden and the number of re-entrant regions was analyzed. Local LGE density was computed and characterized at re-entrant sites. All patients underwent catheter ablation targeting re-entrant regions, the procedural endpoint being AF termination. Clinical, CMR, and ECGI predictors of acute procedural success were then analyzed.ResultsLeft atrial (LA) LGE burden was 22.1 ± 5.9% of the wall, and LA volume was 74 ± 21 ml/m2. The number of re-entrant regions was 4.3 ± 1.7 per patient. LA LGE imaging was significantly associated with the number of re-entrant regions (R?= 0.52; p?= 0.001), LA volume (R?= 0.62; p?< 0.0001), and AF duration (R?= 0.54; p?= 0.0007). Regional analysis demonstrated a clustering of re-entrant activity at LGE borders. Areas with high re-entrant activity showed higher local LGE density as compared with the remaining atrial areas (p?< 0.0001). Failure to achieve AF termination during ablation was associated with higher LA LGE burden (p?< 0.001), higher number of re-entrant regions (p?< 0.001), and longer AF duration (p?= 0.008).ConclusionsThe number of re-entrant regions during AF relates to the extent of LGE on CMR, with the location?of?these regions clustering to LGE areas. These characteristics affect procedural outcomes of ablation.Graphical abstractDisplay Omitted