Discussion
The anatomic proximity of esophagus to the LA especially the LIPV contributes to the formation of esophageal thermal injury. It usually descends rear of the left atrium and slightly right to the aorta, the encircled esophagus resembles a fountain surrounded by the LIPV,spine and aorta.[6] During ablation procedure at the LIPV,balloon occlusions extends the fast ice formation into the PV itself. Therefore, when the balloon is placed deeper, collateral damage, especially esophageal damage, will be more severe.[7] In our case, the patient‘s left atrium was enlarged and esophagus was highly adjacent to the LIPV which explains the esophageal lesions locating at the anterior wall (Figure 2). A vast of approaches could be deployed to evaluate the relationship between the esophagus and LA including computerized tomography, intracardiac echocardiography(ICE). In addition, during the operation, the relationship among the esophagus and LA and the ablation catheter will not be stable, and the mechanical pressure from the freezer balloon may compress the esophagus and shorten the distance between the two,in order to obtain the relationship in real time, the barium paste would be a suitable choice[8].