Analysis of the Depth of Thermal Injuries Caused during the Cardiac Ablation Procedure with the Cooling of the Esophageal Wall

Atrial fibrillation is a heart disease commonly treated by the radiofrequency cardiac ablation (CARF) method, and lesions in the esophagus are frequent consequences of the procedure. The conduction of the ablator electrode's heat promotes the appearance of high temperatures in regions that include the left atrium, the esophagus, and the connective tissue between them. The present study proposes an analysis of the thermal lesion’s depth in these tissues during the CA procedure considering the cooling of the esophageal wall (EW) in all simulation scenarios.  The two-dimensional computer simulation used constant voltage, and the maximum simulated temperatures at the tip of the electrode were 60°C, 80°C, and 100 °C. The cooling temperature in the EW is 0°C. The simulated distances between the tip of the electrode and the EW were: (i) 5 mm and (ii) 2.5 mm.  When the EW was kept at 0 °C, the lesion size decreased by an average percentage of 52.19% in scenario i and 61.07% in scenario ii. Esophageal temperature decreased by at least 30% in both scenarios. The study showed potentially positive results for the use of cooling applied in EW during CA since the prevention of unnecessary tissue overheating might help decrease the risk of severe injuries to the patient.