Atrial Fibrillation as a Potential Risk for ST-Segment Elevation Myocardial Infarction

Abstract

An 83-year-old woman presented with dyspnea that had developed 5 days earlier. Electrocardiography suggested ST-segment elevation myocardial infarction with underlying rhythm of atrial fibrillation (A). Angiography revealed multiple large filling defects in the mid-left anterior descending (LAD) artery and diagonal branch with sluggish coronary flow (B, Online Video 1). Intravascular ultrasound scanning performed after thrombosuction demonstrated only minimal plaque burden with intact intima throughout the LAD, favoring coronary embolization rather than in situ thrombotic occlusion as the cause of this infarction (C). Although mobile echogenic masses (1.0 2.0 cm) in the left atrial appendage (LAA) were suspected on transesophageal echocardiography, the presence of thrombi was slightly inconclusive (D, Online Videos 2 and 3). On arterial phase computed tomography angiograms, a large filling defect in the dilated LAA was detected, which could be caused by blood stasis or thrombi (E, F). This filling defect was, however, persistent on the additional delayed images (G), providing additional evidence of the presence of thrombi (1). She received an anticoagulation therapy after thrombosuction instead of dual-antiplatelet treatment along with stent implantation.