P1393Prolonged atrial electrical conduction as a predictor of atrial fibrillation after atrioventricular nodal reentrant tachycardia ablation

Abstract

BACKGROUND Patients (pts) with atrioventricular nodal reentrant tachycardia (AVNRT) have a higher incidence of atrial fibrillation (AF) during follow-up. Conventional risk factors can play a role in AF development, however atrial electrical conduction properties may be implicated in AF pathogenesis. AIMS to evaluate atrial conduction times and assess its effect on AF development during follow-up. METHODS We studied AVNRT pts who performed EPS and catheter ablation of the slow pathway between 2013 and 2016 in a single center. Pts with AF or valvular disease were excluded. We evaluated duration of symptoms due to AVNRT, conventional risk factors for AF (age, gender, obesity, hypertension, diabetes and structural heart disease (SHD)), left atrium (LA) enlargement and electrophysiologic study (EPS) time intervals related with atrial electrical conduction properties. We measured the time interval between: (1) the beginning of the P wave on the ECG to the A deflection in His-bundle electrogram (P-AHis); (2) the beginning of the P wave to the mid-distal coronary sinus (CS) atrial electrogram (P-CS) and (3) the beginning of the P wave to the H deflection in His-bundle electrogram (P-HHis). RESULTS Fifty-two pts were evaluated during a median follow-up of 63 months (IQR 51-69): 22% male, median age 55 years (IQR 42-67). AF occurred in 9 patients (17%) (39 cases per 1000 person-years). Patients with AF were older (67 vs 53 years, p= 0.005) and had more frequently LA enlargement (33% vs 7%, p= 0.024) but they did not differ in hypertension, obesity, diabetes, SHD and duration of symptoms. EPS measured intervals P-AHis and P-HHis interval were not different between the groups (26.0 vs 22.8 ms, p = 0.89 and 151 vs 106 ms, p= 0.56, respectively) but P-CS were prolonged in patients with AF (70 vs 55 ms, p = 0.02) (figure 1). Univariate logistic analysis for AF is presented in table 1. There was no interaction between P-CS and LA enlargement (p = 0.87). In multiavariate analysis, only P-CS was independently associated with AF (table). CONCLUSIONS In this group of patients with AVNRT, P-CS, but not other atrial conduction intervals, was independently associated with AF development. The possible role of LA electrical conduction impairment in AVNRT pts for AF development needs further studies. Univariate and multivariate analysis Univariate analysis Multivariate analysis OR 95% CI p-value OR 95% CI p-value Age (years) 1.10 1.02-1.19 0.016 1.10 1.00-1.21 0.051 LA enlargement 7.00 1.10-44.71 0.040 3.42 0.41-28.03 0.255 P-CS 1.07 1.021.14 0.013 1.06 1.01-1.12 0.044 OR Odds ratio. CI: confidence interval Abstract Figure. Box-plot for the studied intervals