Thrombus in Left Atrial Appendage (LAA)

Abstract

A thrombus is identified in the left atrium during CMR examination of a 70 years old lady with atrial fibrillation and LV dysfunction. The left atrium was severely enlarged (289 ml, 170 ml/m2) with a lobulated filling defect found in the left atrial appendage in the first pass perfusion image of the heart. Patients with significant enlargement of the left atrium especially when having atrial fibrillation and poor LA contractility are typical cases for the clot in the left atrium and dynamic perfusion images followed by the early post contrast images should be applied using 2 chamber multi slices to have the full coverage of the left atrium and left atrial appendage in this standard cardiac image plane. Evaluating delayed enhancement images revealed discrete area of sub-endocardial (ischemic scar in the lateral wall of the left ventricle together with extensive fibrosis of the left atrium extending to the AV node area (Figures 1-3).