In ablation-naive patients with atrial fibrillation, left atrial late gadolinium enhancement was associated with increased electrogram fractionation (coefficient 0.035; P<0.001).
Cross-Sectional (n=40)
Is left atrial late gadolinium enhancement on CMR associated with electrogram abnormalities in patients with atrial fibrillation?
Atrial LGE on CMR is associated with electrogram fractionation in ablation-naive AF patients even without voltage abnormalities, while in post-ablation patients it correlates with low voltage and activation delay.
Effect estimate: coefficient 0.035
p-value: p=<0.001
Background: Conflicting data have been reported on the association of left atrial (LA) late gadolinium enhancement (LGE) with atrial voltage in patients with atrial fibrillation. The association of LGE with electrogram fractionation and delay remains to be examined. We sought to examine the association between LA LGE on cardiac magnetic resonance and electrogram abnormalities in patients with atrial fibrillation. Methods: High-resolution LGE cardiac magnetic resonance was performed before electrogram mapping and ablation in atrial fibrillation patients. Cardiac magnetic resonance features were quantified using LA myocardial signal intensity Z score (SI-Z), a continuous normalized variable, as well as a dichotomous LGE variable based on previously validated methodology. Electrogram mapping was performed pre-ablation during sinus rhythm or LA pacing, and electrogram locations were coregistered with cardiac magnetic resonance images. Analyses were performed using multilevel patient-clustered mixed-effects regression models. Results: In the 40 patients with atrial fibrillation (age, 63.2±9.2 years; 1312.3±767.3 electrogram points per patient), lower bipolar voltage was associated with higher SI-Z in patients who had undergone previous ablation (coefficient, −0.049; P <0.001) but not in ablation-naive patients (coefficient, −0.004; P =0.7). LA electrogram activation delay was associated with SI-Z in patients with previous ablation (SI-Z: coefficient, 0.004; P <0.001 and LGE: coefficient, 0.04; P <0.001) but not in ablation-naive patients. In contrast, increased LA electrogram fractionation was associated with SI-Z (coefficient, 0.012; P =0.03) and LGE (coefficient, 0.035; P <0.001) only in ablation-naive patients. Conclusions: The association of LA LGE with voltage is modified by ablation. Importantly, in ablation-naive patients, atrial LGE is associated with electrogram fractionation even in the absence of voltage abnormalities.
Kuo et al. (Wed,) conducted a cross-sectional in Atrial fibrillation (n=40). Left atrial late gadolinium enhancement (LGE) vs. Lower signal intensity or absence of LGE was evaluated on Electrogram abnormalities including bipolar voltage, activation delay, and fractionation (coefficient 0.035, p=<0.001). In ablation-naive patients with atrial fibrillation, left atrial late gadolinium enhancement was associated with increased electrogram fractionation (coefficient 0.035; P<0.001).