Abstract 17728: Distribution and Predictors of Left Atrial Low Voltage Areas in Patients With Atrial Fibrillation Undergoing Catheter Ablation

Abstract

Background: Low voltage areas (LVAs) in the left atrium (LA) are associated with a higher likelihood of non-pulmonary vein triggers for atrial fibrillation (AF), and ablation of LVAs has been shown to reduce AF recurrence. This study aimed to assess the distribution and predictors of LVAs in a large cohort of patients undergoing AF ablation. Methods: This study included patients who underwent first AF ablation at the Hospital of the University of Pennsylvania between November 2020 and December 2022. Patients with prior LA ablation, cardiac surgery, sarcoidosis, or amyloidosis were excluded. All patients underwent voltage mapping with multipolar mapping catheters and pulmonary vein isolation. LVAs were defined as contiguous areas with a bipolar voltage <0.5mV. The associations between preprocedure risk factors, echocardiographic findings, and LVAs were assessed using univariable logistic regression. All variables with a p value <0.1 were entered in a stepwise, backward, multivariable model. Results: A total of 857 consecutive patients (mean age: 64.7 years, 34% women, 33% non-paroxysmal AF) were included. LVAs were identified in 132 (15.4%) patients, of whom 72% had LVAs in posterior wall, 47.7% in roof/anterior, 43.9% in septum, 24.2% in floor/inferior, and 16.7% in lateral wall. The multivariable model showed that age (OR per 1 year increase 1.05, 95% CI 1.03-1.08), heart failure/left ventricular cardiomyopathy (OR 2.1, 95% CI 1.4-3.3), sinus node dysfunction (OR 3.7, 95% CI 1.8-7.3), persistent/permanent AF (OR 3.2, 95% CI 2.1-4.9), and severe LA enlargement on echocardiography (OR 1.9, 95% CI 1.1-3.5) were independent predictors of LVAs. Conclusion: LVAs are identified in 15% of patients undergoing first AF ablation and are typically located along the posterior and anteroseptal LA. Presence of LVAs can be anticipated using a readily available preprocedure risk assessment. This information may influence preprocedure planning and choice of ablation strategy.