LAUSR

© BMJ Publishing Group Limited 2022. No commercial reuse. See rights and permissions. Published by BMJ. DESCRIPTION A 62yearold man underwent coronary CT angiography for evaluation of suspected atherosclerotic coronary artery disease (CAD). While no obstructive CAD was noted, a unique left atrial anomaly was incidentally observed. A smooth hypodense fibromuscular bandlike structure was noted within the left atrium, connecting the anteromedial and posterior walls of the left atrium and partially covering the right inferior pulmonary vein (RIPV) ostium (figures 1 and 2). The left atrial band is a rare congenital anomaly with an incidence of 2% in autopsy studies. In most of the described cases, the band is seen connecting the left atrial aspect of the fossa ovalis with various areas of the left atrial endocardium. Various histopathological studies have demonstrated that these bands are composed of fibromuscular tissue. Although a benign entity, it has potential clinical implications. It is associated with the presence of Chiari network, premature atrial complexes, patent foramen ovale, mitral valve prolapse and regurgitation and episodes of cardioembolism. 2 The presence of the left atrial band, especially in relation to the pulmonary venous ostia as seen in the current case, can pose technical challenges during radiofrequency catheter ablation in the setting of atrial fibrillation. The present case highlights the role of CT angiography in the complete anatomical depiction of the left atrium and associated anomalies.