Left atrial catheter ablation including pulmonary vein isolation is a standard therapy in the management of symptomatic atrial fibrillation; however thermal esophageal injury is a known potential consequence of this procedure. Delivery of radiofrequency (RF) energy necessary to perform left atrial ablation has the potential to cause injury to the nearby esophagus including ulceration, hematoma, spasm, esophageal motility disorders, and, in the most extreme case, atrial-esophageal fistula.Esophageal mucosal lesions are the likely precursor to AEF, and esophageal mucosal lesions have been detected on post-ablation endoscopy after pulmonary vein isolation with an incidence ranging from 3% to 60%.

Active esophageal cooling during RF ablation as a means of esophageal injury prevention has been investigated through mathematical models, pre-clinical studies, and in clinical trials. Existing data support the efficacy of this approach, but the practice has not been widely adopted due to lack of a commercially available device.

The aim of this study is to evaluate the impact on procedural efficiency of ablation procedures performed using esophageal heat transfer to warm the esophagus during left atrial cryoablation.

This study is a prospective, pilot study using the Attune Medical ensoETM esophageal heat transfer device to actively warm the esophagus during cryoablation procedures. This design is appropriate to gather the data needed regarding overall procedural time, compare this to historical controls, and estimate a sample size for a larger study powered for statistical significance.

Once patient consent is obtained, the subject will undergo preparation and anesthesia procedures following standard practice. Once the patient is intubated, the esophageal heat transfer device will be placed into the esophagus according to the IFU. The device will remain in place until the ablation procedure is completed and will be removed before extubation. Left atrial cryoablation using the standard approach will be performed with the ensoETM set at a temperature of 42 degrees C.

All patients will be followed up in total for 6 weeks (Long Term FU visit) after the procedure to document any clinical complication related to thermal esophageal injuries if applicable.

Inclusion Criteria:

• Adult patients (age over 18 years).
• Undergoing cryoablation for the treatment of atrial fibrillation, including pulmonary vein isolation.
• Patients must be able to understand and critically review the informed consent form.
• Subjects must understand and agree to study requirements and sign a written informed consent.

Exclusion Criteria:

• Patients who are unable to provide informed consent.
• Significant co-morbidities that preclude standard ablation procedure.
• Patients with <40 kg of body mass.
• Patients with relevant esophageal pathology (e.g. esophageal cancer).