LAA thrombi in AF

Q: What percentage of left atrial thrombi in atrial fibrillation (AF) originates from Left Atrial Appendage? (select one)

A) 50%

B) 70%

C) 90%

Answer: C

The objective of asking this question is to cover two concepts.

First, as 90% of thrombi in AF originate in the LAA, it is a good practice in cardiac surgery to ligate, amputate, or occlude the LAA if the patient already has an open sternum for other indications, particularly in those patients who cannot take oral anticoagulation. Other patients who are not undergoing cardiac surgery may get such ablation/occlusion via procedures such as the WATCHMAN device.

Second, clinicians should be mindful that 10% of thrombi are NOT coming from the LAA and should evaluate the caveats. It may be left atrial structural or functional abnormalities or a hypercoagulable state. Also, if the LAA is not properly amputated, residual communication between the LAA and Left Atrium (LA)—known as residual jet—can lead to stroke. A residual jet >5 mm may predispose to thrombus formation. 

#cardiology

#cardiac-surgery

References:

1. Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg 1996; 61:755.

2. Saraf K, Morris GM. Left Atrial Appendage Closure: What the Evidence Does and Does Not Reveal-A View from the Outside. Interv Cardiol Clin. 2022 Apr;11(2):171-183. doi: 10.1016/j.iccl.2021.11.009. Epub 2022 Mar 11. PMID: 35361462.

3. Dudziñska-Szczerba K, Kułakowski P, Michałowska I, Baran J. Association Between Left Atrial Appendage Morphology and Function and the Risk of Ischaemic Stroke in Patients with Atrial Fibrillation. Arrhythm Electrophysiol Rev. 2022 Apr;11:e09. doi: 10.15420/aer.2022.08. PMID: 35846423; PMCID: PMC9272406.