BACKGROUND The presence of low voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) after pulmonary vein isolation. Numerous studies have posited a link between gastroesophageal reflux disease (GERD) and AF, attributing this relationship to the anatomical proximity of the esophagus to the posteroinferior wall of the LA. OBJECTIVE The objective of this study was to investigate whether GERD can predict the presence of LVZs in the posteroinferior wall of the LA. METHODS Five hundred fifty-one patients with persistent AF, scheduled for their first AF ablation procedure, were prospectively enrolled. Voltage maps were collected using a multipolar catheter, and LVZs were defined as areas measuring >= 3 cm(2) with a peak-to- peak bipolar voltage of < 0.5 mV. Information on GERD symptoms was collected from the participants through a self-administered questionnaire. RESULTS Long-standing persistent AF was present in 22.3% of the total cohort. GERD was present in 29% of patients and LVZs in the posteroinferior wall in 12.7%. In the multivariable analysis, patients with GERD were found to have more than twice the odds (odds ratio 2.26; 95% confidence interval 1.24-4.13; P 5 . 008) of exhibiting LVZs in the posteroinferior wall of the LA than patients without GERD. GERD was not associated with LVZs in any other region of the LA. CONCLUSION GERD was found to be independently associated with LVZs in the posteroinferior LA. This association may be attributable to inflammation and may partly explain the link between GERD and AF. (c) 2024 Heart Rhythm Society. Published by Elsevier Inc.