Cardiac arrest resulting from an unidentified foreign object, later identified as a balloon cover, within the left anterior descending coronary artery.

A 31-year-old man with a history of hypertrophic cardiomyopathy and alcohol septal ablation one week before was presented after an out of hospital cardiac arrest in the setting of an anterior wall ST-elevation myocardial infarction. Immediate coronary angiography showed an unidentified foreign object within the left anterior descending coronary artery (LAD), later identified as the cover of a balloon that had been unintentionally inserted and abandoned within the LAD during the alcohol septum ablation one week earlier. Intracoronary imaging confirmed the presence of endothelial damage and thrombus formation within the LAD explaining acute myocardial infarction. The patient was treated by surgical retrieval of the balloon cover, extended septal myectomy and coronary artery bypass grafting (CABG) of the LAD. This case is both an example of unintentional neglect of unexpected objects, and the importance of multimodality imaging and multidisciplinary teamwork to get to a correct diagnosis and treatment.