Esophagus imaging for catheter ablation of atrial fibrillation: comparison of two methods with showing of esophageal movement
This study aims to evaluate whether visualization and integration of the computed tomography (CT) scan of the left atrium (LA) and the esophagus into the three-dimensional (3D) electroanatomical map the day before ablation is accurate compared with integration of an esophagus tag into the electroanatomic LA map visualizing the anatomic relationship during the radiofrequency ablation or whether esophagus movement prohibits esophagus visualization the day before ablation. Eighteen patients with highly symptomatic atrial fibrillation underwent cardiac CT imaging the day before pulmonary vein ablation. Before CT imaging, a gastric tube was introduced into the esophagus allowing its CT 3D reconstruction. During radiofrequency ablation, mapping of the esophagus was performed and integrated into the LA 3D map. By comparing the position of the gastric tube during CT on day 1 with real-time anatomical mapping using a 3D navigation catheter on day 2, an average distance of more than 10 mm was found in six of 18 patients (33%). In six of 18 (33%), the maximal distance between day 1 and day 2 was even more than 15 mm. Reliance on CT images, even if acquired within 24 h before ablation, does not ensure adequate intraprocedural localization of the esophagus or enhance recognition of esophageal motility.