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

JACC Clin Electrophysiol. 2018 Jan;4(1):17-29. doi: 10.1016/j.jacep.2017.07.019. Epub 2017 Nov 6.


Objectives: This study sought to assess the relationship between fibrosis and re-entrant activity in persistent atrial fibrillation (AF).

Background: The mechanisms involved in sustaining re-entrant activity during AF are poorly understood.

Methods: Forty-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.

Results: Left 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).

Conclusions: The 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.

Keywords: atrial fibrillation; atrial fibrosis; electrocardiographic mapping; magnetic resonance imaging; re-entry; rotor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Atrial Fibrillation* / diagnostic imaging
  • Atrial Fibrillation* / epidemiology
  • Atrial Fibrillation* / physiopathology
  • Atrial Fibrillation* / surgery
  • Cardiac Imaging Techniques
  • Cardiomyopathies* / diagnostic imaging
  • Cardiomyopathies* / epidemiology
  • Catheter Ablation
  • Electrocardiography*
  • Female
  • Gadolinium / therapeutic use
  • Heart Atria / diagnostic imaging
  • Heart Atria / physiopathology
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged


  • Gadolinium