Patients with documented atrial fibrillation who were referred to our clinic for catheter ablation will undergo standard HPSD ablation and subsequent esophagoscopy.

After esophagoscopy patients will be followed up for one month in the form of a telephone follow-up.

The primary endpoint of the study assessed by esophagoscopy performed on the day after the index catheter ablaton is the incidence of esophageal thermal lesions.

Secondary endpoints include:

1. The size of the esophageal thermal lesions.
2. The severity of esophageal thermal lesions.

Inclusion Criteria:

• Atrial fibrillation documented in the 12-lead ECG
• Indication for catheter ablation in accordance with currentn ESC guidelines

Exclusion Criteria:

• Pregnancy
• Women of childbearing potential without a negative pregnancy test within 48 hours prior to ablation procedure
• Known intracardiac or other thrombi
• Contraindication to anticoagulation
• Contraindication to esophagoscopy: diseases and deformities of the cervical spine, esophageal varices

All patients with documented atrial fibrillation who were referred to our clinic for pulomary vein isolation