Predictors of low-voltage areas in the left atrium in patients with atrial fibrillation

Abstract Background Low-voltage areas (LVA) in the left atrium (LA) electroanatomical map are potent predictors of the efficacy of atrial fibrillation (AF) ablation. Clinical factors predicting the presence of LVA have moderate accuracy. The aim of the study was to find clinical and echocardiographic factors predicting the presence of LVA in patients undergoing AF ablation. Methods Consecutive unselected patients undergoing AF ablation were included in the retrospective analysis. All patients underwent transthoracic (including LA strains) and transesophageal echocardiography, pulmonary vein isolation and LA electroanatomical mapping using multipolar catheter. LVA were defined as an area greater than 2cm2 with a voltage below 0.5mV (or 0.3mV when measured during AF). Results A total of 432 patients were included in the analysis, 107 (24.8%) had LVA. The mean age of the study population was 62.8 years, 185 patients had nonparoxysmal AF (42.8%). In the univariate logistic regression analysis numerous clinical parameters (age, female sex, presence of heart failure, diabetes, coronary artery disease, AF during examination), echocardiographic parameters (LA reservoir strain - LASr, LA emptying fraction, LA volume index, E/e’, LA appendage velocity - LAAV) and mean LA pressure (measured invasively) were significant predictors of the presence of LVA. In the multivariate logistic regression analysis age (HR 1.11 per 1 year increase, p<0.001), LASr (HR 0.89 per 1% increase, p=0.014) and LAAV (HR 0.93 per 1cm/s increase, p<0.001) were significant predictors of the presence of LVA. In receiver-operator curve (ROC) analysis LASr and LAAV were potent predictors of LVA in patients tested on sinus rhythm (AUC 0.86 and 0.87 respectively), while they had moderate predictive value in patients tested on AF (LASr AUC 0.67, LAAV AUC 0.77). Conclusions Age, LASr, and LAAV were significant predictors of LVA in patients undergoing AF ablation. The predictive value of LASr and LAAV was better in patients examined during sinus rhythm than in patients examined during AF.