A 68-year-old man presented with multiple embolic strokes and sepsis 50 days after catheter ablation of atrial fibrillation. Cardiac computed tomography scan demonstrated an atrioesophageal fistula at the left atrial posterior wall and hypermobile materials with hypoattenuating lesions in the left atrium. On the 12th hospital day, he presented with acute ST-elevation in the inferior leads. A bedside echocardiogram revealed unusually high myocardial echogenecity and akinesia on the right coronary artery territory. These findings disappeared within a few minutes. This case shows characteristic images of coronary air embolism in gas-containing endocarditis caused by atrioesophageal fistula after catheter ablation of atrial fibrillation.