ST-segment elevation myocardial infarction possibly caused by thromboembolism from left atrial appendage thrombus after incomplete surgical ligation.

Coronary embolism (CE) is the underlying cause of 3% of acute coronary syndromes but is frequently overlooked in the differential diagnoses of acute coronary syndromes. The CE may be direct (left sided from the native or prosthetic heart valve, the left atrium, left atrial appendage or pulmonary venous bed), paradoxical (from the venous circulation through a patent foramen ovale, atrial septal defect, ventricular septal defects, cyanotic congenital heart defects or pulmonary arteriovenous malformations), or iatrogenic (following cardiac interventions. In patients with atrial fibrillation (AF), left atrial appendage (LAA) ligation during mitral valve surgery has long been recommended to decrease the future risk of embolic events such as myocardial infarction or ischemic stroke. Recently, Aryana et al reported that in patients with AF who underwent surgical ligation of LAA, the presence of incomplete ligation was associated with a significantly higher risk of stroke/systemic embolization than complete ligation (24% vs 2%).