Left atrial epicardial adipose tissue exacerbates electrical conduction disturbance in normal‐weight patients undergoing pulmonary vein isolation for atrial fibrillation.

Introduction: Epicardial adipose tissue (EAT) exacerbates both electrical and structural remodeling in obese atrial fibrillation (AF) patients, but the impacts of EAT on atrial arrhythmogenicity remain unclear in normal‐weight AF patients. Therefore, we sought to investigate this issue using electroanatomic mapping. Methods and Results: We enrolled drug‐refractory 105 paroxysmal AF patients in the normal body mass index range (18.5–24.9 kg/m2), who had undergone electroanatomic mapping after pulmonary vein isolation (PVI). One day before PVI, we assessed P‐wave duration in a 12‐lead electrocardiogram and left atrial (LA)‐EAT volumes using contrast‐enhanced computed tomography. The patients were divided into two groups based on the median LA‐EAT volume (16.0 ml); the high LA‐EAT group (≥16.0 ml, n = 53) and low LA‐EAT group (<16.0 ml, n = 52). We compared P‐wave duration, LA conduction velocity and bipolar voltage, the presence of low‐voltage zone (<0.5 mV), and LA volume index on echocardiography between the two groups. The LA bipolar voltage, low‐voltage zone, and LA volume index were not different between the high and low LA‐EAT groups. However, P‐wave duration was significantly longer in the high group than in the low group (p <.001). Additionally, the LA conduction velocity was significantly more depressed in the high group than in the low group (p <.001). Multivariate linear regression analysis revealed that LA‐EAT volume was correlated with P‐wave duration (β =.367, p <.001) and conduction velocity (β = −.566, p <.001), respectively. Conclusions: Increased LA‐EAT volumes were associated with electrical conduction disturbance after PVI in normal‐weight patients with AF. P‐wave duration may be a clinically useful predictor of LA‐EAT. [ABSTRACT FROM AUTHOR]