Use of Computed Tomography Scan to Rule Out Phantom Thrombus in the Left Atrial Appendage

Abstract

Objective: The aim of study was to evaluate the utility of CT scan with delayed acquisition protocol to exclude LAA thrombus. The occurrence of left atrial appendage (LAA) thrombus is a frequent complication of atrial fibrillation (AF) and increases the thromboembolic risk. Transesophageal echocardiography (TEE) is considered the gold standard to ensure that this chamber is thrombus-free. Multidetector computed tomography (CT) scan has some advantages, such the possibility to get 3D reconstruction and explore other structures in relationship with the LAA. However, there is a lack of specificity in case of false positive images with filling defects due to slow velocities in the LAA. Methods and Results: Thirty-four patients with suspected thrombus by a previous CT scan or transesophageal echocardiogram were included in the study. In all of patients, complete LAA filling was observed, with sensitivity, specificity and negative predictive value of 100% to differentiate circulatory stasis from thrombus. Conclusion: Performing a CT scan with delayed acquisition protocol and in prone position are safe techniques to discard false thrombus.

Keywords

• atrial fibrillation
• thrombus
• left atrial appendage
• computed tomography