Measuring luminal esophageal temperature during pulmonary vein isolation of atrial fibrillation

AIM: To investigate the luminal esophageal temperature (LET) at the time of delivery of energy for pulmonary vein isolation (PVI). METHODS: This study included a total of 110 patients with atrial fibrillation who underwent their first PVI procedure in our laboratory between March 2010 and February 2011. The LET was monitored in all patients. We measured the number of times that LET reached the cut-off temperature, the time when LET reached the cut-off temperature, the maximum temperature (T max) of the LET, and the time to return to the original pre-energy delivery temperature once the delivery of energy was stopped. RESULTS: Seventy-eight patients reached the cut-off temperature. It took 6 s at the shortest time for the LET to reach the cut-off temperature, and 216.5 ± 102.9 s for the temperature to return to the level before the delivery of energy. Some patients experienced a transient drop in the LET (TDLET) just before energy delivery. Ablation at these sites always produced a rise to the LET cut-off temperature. TDLET was not observed at sites where the LET did not rise. Thus, the TDLET before the energy delivery was useful to distinguish a high risk of esophageal injury before delivery of energy. CONCLUSION: Sites with a TDLET before energy delivery should be ablated with great caution or, perhaps, not at all.