Findings and outcome of fluoroscopic visualization of the oesophageal course during catheter ablation of atrial fibrillation

AIMS: The close topographic relationship between the left atrial posterior wall (LAPW) and the oesophagus creates a potential hazard of thermal lesions to the oesophagus during radiofrequency (RF) catheter ablation of atrial fibrillation (AF). The purpose of the study was to describe topographic relation of the oesophagus behind the left atrium in the ablation situation, and to evaluate the clinical outcome of subsequent modifications to the strategy using continuous real-time fluoroscopic visualization of the oesophageal course. METHODS AND RESULTS: In 214 consecutive patients, a gastric tube (GT) was inserted before circumferential pulmonary vein isolation (CPVI) for the treatment of paroxysmal (n= 160) or persistent (n= 54) AF. In the real-time mapping situation at the LAPW, the tissue interface between catheter tip and oesophagus lumen measured only 2.9 ± 1.9 mm, and 2.5 ± 1.2 mm at the level of the upper and lower pulmonary vein (PV) ostia, respectively. Modifications of the intended antral CPVI approach due to an oesophageal course close to the left or right PV ostia (in 76.6% of patients) were associated with reduced success rate (sustained sinus rhythm) after one (54.9 vs. 72.0%, P = 0.03), or 1-3 ablation procedures (85.4 vs. 96.0%, P = 0.04) during a mean follow-up of 13 ± 10 months. CONCLUSION: Continuous real-time fluoroscopic visualization using a GT emphasizes the very small distance of the catheter tip and oesophageal lumen that may be present in the real-ablation situation and may help to avoid RF lesion application in close proximity to the oesophagus. However, accordant modification of AF ablation strategy may reduce efficacy of the procedure.