Four Accessory Left Atrial Appendages.

When a patient is to undergo percutaneous left atrial appendage (LAA) closure, it is important to have a thorough understanding of the LAA's anatomy and neighboring cardiac structures. A 65-year-old man was referred for cardiac computed tomography (CCT), which showed significant stenosis in the left circumflex coronary artery (Picture 1A, yellow arrow). He had an LAA with dimensions of 41 by 17 mm (Picture 1, 2A). He also had four accessory LAAs (Picture 1, 2B-E) with dimensions of 8 by 6 mm (blue arrows), 15 by 8 mm (arrowheads), 15 by 9 mm (asterisks), and 24 by 8 mm (arrow). Definite thrombus was not found in the accessory LAAs. On CCT, focal outpouchings of the LA wall are classified into two types: accessory LAAs and LA diverticula. Accessory LAAs have been defined as outpouchings showing a discernible ostium with a neck and body displaying irregular contours suggestive of pectinate muscles, as in our case; LA diverticula are defined as outpouchings with a saclike structure and a broad-based ostium and smooth body contour (1). Some reports have indicated that a single accessory LAA can be a source of thromboembolism (2). Patients with four accessory LAAs are extremely rare. The theoretical risk of thrombosis within accessory LAAs is higher in cases with multiple accessory LAAs. Therefore, physicians interpreting CCT images should be alert for this anatomical abnormality.

Picture 1.

Picture 2.

The authors state that they have no Conflict of Interest (COI).