Comparison of computed tomography imaging with intraprocedural contrast esophagram: implications for catheter ablation of atrial fibrillation.

BACKGROUND: Computed tomography (CT) has been used to localize the esophagus before radiofrequency ablation (RFA) of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to compare esophageal imaging by CT versus esophagram. METHODS: CT imaging of the left atrium was performed in 57 patients 1 week before RFA and was imported into the CARTO mapping system. The electrophysiologist created a virtual shell of the left atrium and pulmonary veins (PVs) that was merged with the CT image; however, the CT-defined location of the esophagus was not displayed. The patient was then given 10 mL of oral contrast. Using fluoroscopy, an electroanatomic catheter tagged the esophageal borders outlined by esophagram. The CT-defined esophagus was then imported, and the borders were tagged on the merged map. In this manner, the esophagus borders by esophagram versus those by CT were compared. RESULTS: The maximum diameter of the esophagus by esophagram versus CT was not different (16.3 +/- 3.4 vs. 16.5 +/- 3.1 mm; P = .7). The esophagus was near the left PVs in 34 (62%), center in 13 (24%), and near the right PVs in eight (15%) patients. There was concordance between CT and esophagram in 48 of 55 patients (87%; P = .2). Ye, in 21 (44%) of 48 patients with concordant location, the CT-defined esophageal borders were separated from the esophagram-defined borders by >or=50% of the esophagus diameter. CONCLUSIONS: Reliance on remotely acquired CT images does not ensure adequate intraprocedural localization of the esophagus or enhance recognition of esophageal motility.

Successful ablation of focal left atrial tachycardia using Stereotaxis Niobe remote magnetic navigation system.

Stereotaxis Niobe remote magnetic navigation system (MNS) (St Louise, USA), is a new technology that has applications in the field of catheter based ablation treatment of cardiac arrhythmias. Most if not all data on the feasibility, safety, and efficacy of the Stereotaxis Niobe MNS comes from select centres where highly skilled personnel have acquired considerable experience using this technology. Herein, we report a case where the Stereotaxis Niobe MNS was successfully used to perform remotely-controlled high density three-dimensional electroanatomical mapping and radiofrequency ablation of a focal atrial tachycardia originating from the anteroseptal region of the left atrium.