# Late gadolinium enhancement in areas with electrically fractionated potentials during sinus rhythm in patients with atrial fibrillation

## TL;DR

This study investigates the relationship between electrically fractionated potentials and late gadolinium enhancement in patients with atrial fibrillation, finding that these areas are associated with higher LGE heterogeneity and increased AF recurrence.

## Contribution

The study identifies that areas with electrically fractionated potentials in AF patients show higher LGE heterogeneity and volume ratio compared to non-fractionated areas.

## Key findings

- LGE entropy and volume ratio were significantly higher in AEFP compared to non-AEFP.
- AF recurrence was more common in patients with more than three AEFP.
- Atrial voltages did not differ between AEFP and non-AEFP areas.

## Abstract

The areas with electrically fractionated potentials (AEFP) during sinus rhythm are related to non-pulmonary vein triggers and may serve as substrates of atrial fibrillation (AF) maintenance. However, the histological properties of these compounds remain unclear. Therefore, we aimed to evaluate the late gadolinium enhancement (LGE) properties of AEFP in patients with AF. We enrolled 15 patients with AF who had undergone LGE magnetic resonance imaging before catheter ablation. AEFP in the left atrium was detected using the HD-Grid and NavX systems after pulmonary vein isolation. We compared LGE properties between AEFP and the surrounding non-fractionated areas (non-AEFP). LGE heterogeneity and density were evaluated through entropy (LGE entropy) and the volume ratio of the enhancement voxel (LGE volume ratio), respectively. Thirty-three AEFP were detected in the left atrium. LGE entropy and LGE volume ratio were significantly higher in AEFP than in non-AEFP [LGE entropy: 6.2 (6.1–6.4) vs. 5.9 (5.8–6.0), p ≤ 0.0001; LGE volume ratio: 23.0% (17.2–29.0%) vs. 10.4% (3.4–20.2%), p ≤ 0.0001]. The atrial voltages did not differ [2.4 (1.3–3.7) vs. 2.5 (1.9–3.1) mV, p = 0.96]. AF recurrence was more significantly found in patients with more than three AEFP than in those without it (log-rank test: p = 0.009). AEFP is likely to be distributed in heterogeneous and moderate LGE areas, regardless of the atrial voltage.