 The purpose of this study is to prospectively follow the next 200 patients who undergo catheter ablation of atrial fibrillation and endoscopy. If any signs of esophageal injury are seen on endoscopy the patients will be treated with omeprazole and sucralfate and they will have repeat endoscopy in two weeks. Patients who do not have any esophageal injury will be contacted by telephone in two weeks to be assessed for GI symptoms. 