This apical 4-chamber view obtained from a patient with end-stage kidney disease during physical examination demonstrates some hyperechoic structure in the left atrium resembling a Q-tip. Is it abnormal?

It is a prominent left atrial ridge (LAR), an anatomic variant. LAR, also known as Coumadin ridge is a band-like tissue that lies in the left atrium in between the left superior pulmonary vein and left atrial appendage (LAA). It usually has a narrow proximal portion and a bulbous distal portion resembling a cotton swab. Coumadin ridge can be misdiagnosed as a thrombus when prominent leading to unnecessary anticoagulation (with Coumadin), and hence the name. It is usually better demonstrated on transesophageal echocardiogram though can be seen on transthoracic echocardiogram in patients with good acoustic windows. On a note of caution, intracardiac masses may rarely arise from the LAR necessitating multimodality imaging for further characterization. Below is the labelled image of the above, two more examples as well as anatomic correlates.