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Saint Thomas Heart

Left Atrial Appendage Closure

Left Atrial Appendage Closure (LAAC) is a treatment strategy to reduce the risk of left atrial appendage blood clots from entering the bloodstream and causing a stroke in patients with non-valvular atrial fibrillation (AF).

In non-valvular AF, more than 90 percent of stroke-causing clots that come from the heart are formed in the left atrial appendage. While the most common treatment for AF stroke risk is treatment with blood-thinning medications, some patients find that blood-thinning medications can be difficult to tolerate or are risky.

In select patients, physicians may determine that an alternative to blood thinners, most often an LAAC implant, is needed to reduce AF stroke risk. LAAC is an implant-based alternative to blood thinners, and, like blood-thinning medications, does not cure AF or completely prevent the risk of stroke.

Closure of Left Atrial Appendage

The left atrial appendage (LAA) is a small, ear-shaped sac in the muscle wall of the left atrium (top left chamber of the heart). In a normal heart, the heart contracts with every heartbeat, and the blood in the left atrium and LAA is squeezed out of the left atrium into the left ventricle (bottom left chamber of the heart).

When a patient has atrial fibrillation, the electrical impulses that control the heartbeat do not travel in an orderly fashion through the heart. Instead, many impulses begin at the same time and spread through the atria. The fast and chaotic impulses do not give the atria time to contract and/or effectively squeeze blood into the ventricles. Because the LAA is a little pouch, blood collects there and can form clots in the LAA and atria. When those blood clots are pumped out of the heart, they can cause a stroke. People with atrial fibrillation are five to seven times more likely to have a stroke than the general population.

If a person is at risk of developing clots in the left atrium/LAA, the cardiologist may recommend a procedure to seal off the LAA. Depending on the implant device selected, the implant is a one-time implant and is similar to a stent procedure. The implant is guided into the heart through a flexible tube, a catheter, inserted through the femoral vein in the upper leg. Then, the implant is introduced into the right atrium and then passed into the left atrium through a small puncture hole. Once the position is confirmed, the implant is released and is permanently fixed in the heart. The implant does not require open heart surgery and does not need to be replaced. Recovery typically takes twenty-four hours.


One of the LAAC devices, The WATCHMAN™ device, is shaped like a jellyfish, and is a self-expanding device made from nitinol (nickel-titanium alloy). The top of the device is covered with a permeable polyester fabric that acts like a filter initially but becomes covered with a patient's own cells within 45 days. There are tines on the outside of the device that act to stabilize and hold it in place.

For more information about the WATCHMAN™ implant as well as to determine if you are a candidate for this type of therapy, please call Saint Thomas Heart at 615-329-5144 (Saint Thomas Midtown) or 615-269-4545 (Saint Thomas West).

Watchman Heart

Watchman Device



* Images use with permission from Boston Scientific