Real-time 3-dimensional imaging of the esophagus and left atrium with a noncontact mapping system.

BACKGROUND Recognizing the relative location of the esophagus to the left atrial posterior wall (LAPW) is required to avoid esophageal injury during atrial fibrillation ablation. METHODS AND RESULTS The 24 patients undergoing circumferential pulmonary vein isolation (CPVI) each had the geometry of their left atrium (LA) and esophagus constructed by a noncontact mapping system with EnSite version 6.0J. The esophageal course relative to the LAPW was found to be to the left in 12, middle in 8, right in 2, and obliquely left-to-right in 2 patients, and in 13 patients (54%) it was located on or near either the left or right CPVI line. The mean distance between the esophagus and LAPW was shorter at the bottom line of the LAPW connecting both inferior pulmonary veins (3 +/- 3 mm) than at the LA roof line connecting both superior pulmonary veins (6 +/- 6 mm, P<0.01). CONCLUSIONS The location of the esophagus relative to the LAPW varies with the patient, but a close location to either CPVI line was found in approximately 50% and a close location between the esophagus and LAPW was found in the inferior and middle locations in most patients.