d t h fi c f p m s W describe a case of a 69-year-old white male with extensive comorbidities, including coronary artery disease and atrial brillation, who was using coumadin and heparin for a recently iagnosed left ventricle thrombus, initially admitted to our hosital with sepsis and ischemic stroke. Two weeks after admission, he patient was noted to have multiple episodes of melena with a rop in hematocrit from 24.4% to 19.9%. Two months prior to this dmission, he had undergone radiofrequency ablation (RFA) for trial fibrillation without complications. An upper gastrointestinal GI) endoscopy was performed, which showed red blood throughut the esophagus, with a fibrinous blood clot protruding through 6 mm mucosal defect in the middle third of the esophagus in bsence of other active bleeding source (Figure A). The lesion was elieved to be highly suspicious for an atrioesophageal fistula AEF). Computed tomography angiogram showed an anomalous ommunication between the esophagus and left atrium (Figure B). computed tomography scan of the brain was performed after he endoscopy for worsening neurological status, which revealed xtensive, multifocal intravascular pneumocephalus within the ortical vessels, dural venous sinuses, subarachnoid space, and the erebral parenchyma (Figure C). These findings were consistent ith air emboli through a cardiac shunt. Surgical repair of AEF as ruled out due to deteriorating neurological condition and oor cardiac function. A decision was subsequently made to proide comfort care only and the patient died shortly thereafter. Atrioesophageal fistula is an uncommon, but serious complicaion of radiofrequency ablation procedure performed commonly or treatment of atrial fibrillation. The incidence has been estiated to be between 0.05% and 1%.1 Symptoms can present 3 days o 41 days after ablation and may include chest pain, fever, melena, nd hematemesis. Neurological sequelae include confusion, seiures, meningitis, and stroke.2,3 Mortality is estimated to be approximately 70%. Causes of death include gastrointestinal bleed, cerebral embolism, and septic shock. Surgical repair of the fistula is the most common treatment. A single case of successful esophageal stenting for esophagomediastinal fistula after ablation has been described.4 Esophageal stent placement was not attempted in his case due to concern that further air insufflation during atempted placement would lead to more air emboli. This case highlights the importance of considering AEF in the ifferential diagnosis of patients presenting with upper gastroinestinal bleeding with or without neurological symptoms who ave undergone recent radiofrequency ablation therapy for atrial brillation. The diagnosis is most often made with upper endosopy. However minimal air insufflation during endoscopy or deerral of endoscopy until AEF is ruled out is advisable to prevent ossible air emboli through an AEF. Reported morbidity and ortality of this rare complication is extremely high and urgent urgical repair is the standard treatment.