A left atrial appendage is a pouch-like structure in the left atrium of the heart. Clots can form in this pouch so some patients are treated with blood-thinner medication to prevent this.

What is a left atrial appendage?

The left atrial appendage (LAA) is a pouch-like structure in the left atrium. There is no known purpose for it, and people function well without it.

Why should a left atrial appendage be closed off?

When people are in atrial fibrillation, the atria (both left and right) are uncoordinated in their contractions, and do not contract fully. This leads to blood clots forming, and scientific studies have shown that majority of these blood clots are formed inside the left atrial appendage during atrial fibrillation. If this clot gets dislodged, it can travel through the heart and up to the brain, resulting in a stroke.

Warfarin is a powerful blood thinner that is often prescribed to people in atrial fibrillation to keep clots from forming in the left atrial appendage. This is an effective medication, but it can have some side effects, including:

  • Blood must be checked frequently to measure the clotting time (International Normalized Ratio also known as INR)
  • Some patients have difficulty maintaining an appropriate INR
  • There is a higher risk of significant bleeding
  • Various foods and medications could affect the metabolism of warfarin and the level of INR

Although there are other types of anticoagulants that do not require blood testing to adjust the dosing, there is a constant risk of bleeding (including life-threatening bleeding such as intracranial bleeding) with any type of blood thinner. This means that blood thinners are not an option for many people as a method of stroke prevention in atrial fibrillation.

What is a left atrial appendage closure?

The left atrial appendage can be closed off with a device so that clots are contained in the left atrial appendage and cannot be dislodged.

This is done in the cardiac catheterization lab under general anesthesia through catheters that are inserted into a vein in the leg.

This can eliminate the need to take Warfarin or other blood thinners, and also decreases the risk of stroke. There are several different devices that can be used. Your physician will advise you whether this procedure is appropriate for you and if so, which device is best for you.


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