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). It is unclear what function, if any, the LAA performs.
In normal hearts, the heart contracts with each 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 blood clots are pumped out of the heart, they can cause a stroke. People with atrial fibrillation are 5 to 7 times more likely to have a stroke than the general population.
Taking a blood thinner, such as warfarin (Coumadin), reduces the risk of stroke in patients with atrial fibrillation. Many patients have concerns about, or dislike, taking warfarin. Some of the reasons for this are:
- Frequent blood draws are needed to measure the patient’s international normal ratio (INR), or clotting time. The tests are needed to make sure the patient takes the right amount of medication.
- While taking warfarin, you need to limit your intake of certain foods that contain vitamin K.
- The risk of bleeding is higher while taking warfarin.
- Some patients do not tolerate warfarin or have trouble maintaining a normal INR.
New medications are available for patients with atrial fibrillation who do not have heart valve disease. These medications are dabigatran (Pradaxa) and rivaroxaban (Xarelto). However, like warfarin, some patients have concerns and problems with these medications, such as:
- Patients who cannot take anticoagulants can not tolerate these medications.
- Some patients are concerned about the cost of the medication.
- These medications also increase the risk of bleeding.
Studies have shown that, among patients who do not have valve disease, the majority of blood clots that occur in the left atrium start in the LAA.
Closure of Left Atrial Appendage
If you are at risk of developing clots in the left atrium/LAA, your doctor may recommend a procedure to seal off your LAA. This can reduce your risk of stroke and eliminate the need to take blood-thinning medication.
There are several options and devices available for closure of the LAA. Your doctor will talk to you about the best options for your individual needs.
The WATCHMAN device has been approved by the FDA:
To reduce the risk of thromboembolism from the LAA in patients with nonvalvular atrial fibrillation who:
- Are at increased risk of stroke and systemic embolism and for whom anticoagulation therapy is recommended;
- Have physician approval to take warfarin; and
- Have an appropriate reason to want treatment with a non-medication alternative to warfarin, taking into account the safety and effectiveness of the device compared to warfarin.
The WATCHMAN Device is a parachute-shaped, self-expanding device that closes the LAA. It was tested in several studies that showed the device was a good alternative treatment for patients who cannot tolerate treatment with warfarin.
The WATCHMAN device is implanted percutaneously (through the skin) in the electrophysiology (EP) lab. The implant procedure does not require surgery; however, general anesthesia may be used during the procedure. A catheter sheath is inserted into a vein near the groin and guided across the septum (muscular wall that divides the right and left sides of the heart) to the opening of the LAA. The device is placed in the opening of the LAA. This seals off the LAA and keeps it from releasing clots.
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Posted with permission from Boston Scientific
If you are interested in treatment with the WATCHMAN device, you will need an evaluation by the electrophysiologists and nurses in the High-Risk Anticoagulation Clinic. This is a specialized clinic in Cleveland Clinic’s Center for Atrial Fibrillation.
Some important information about the WATCHMAN procedure:
- You will stay in the hospital overnight after the procedure.
- You will need to take aspirin and warfarin until you have your follow-up appointment.
- You will have a transesophageal echo (TEE) within 48 hours of the procedure.
- Your first follow-up appointment is 45 days after the procedure. Another TEE will be done at this appointment. If the TEE shows that the LAA is blocked, you will be able to stop taking warfarin and start taking clopidogrel (Plavix) for 6 months. After 6 months, you will stop taking clopidogrel, unless you need to take it for another reason. You will continue daily treatment with aspirin.
- If the TEE shows that the LAA is not blocked, you will continue taking warfarin and have another TEE and follow-up appointment after 6 months.
- Once the LAA is blocked, you will have a yearly follow-up appointment in the clinic.
- You will need an echocardiogram (echo) within 60 days of your procedure.
The LARIAT procedure is another percutaneous procedure used to close of the LAA. Implantation of this device is performed under anesthesia.
The LARIAT procedure involves a special guidewire system. A catheter is inserted through a vein at the groin an advance across the septum to the LAA. A second wire is inserted below the breastbone into the space surrounding your heart. The cardiologist uses these wires to stabilize the LAA. Then, the LARIAT device is used to lasso, or place, a stitch loop around the LAA to close it off. This keeps clots from leaving the LAA.
You will need an evaluation to find out if the LARIAT procedure is the best treatment option for you. This is done by the electrophysiologists and nurses in Cleveland Clinic’s Center for Atrial Fibrillation.
Unlike the procedure that uses the WATCHMAN device, you do not need to take warfarin after the LARIAT procedure.
You will need to have the following tests:
- Brain MRI or CT Scan within 90 days of the procedure if you have a history of stroke or TIA
- Transesophageal echo (TEE) within 48 hours of the procedure
You will spend the night in the hospital after the procedure.
Your first follow-up appointment will be 45 days after your procedure and you will have a TEE during that visit. You will have another TEE and office visit 6 months after the procedure and a yearly follow-up appointment in the clinic.
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AtriClip: posted with permission from AtriCure
LAA occlusion can benefit patients who need heart surgery and also have atrial fibrillation. The procedure is also helpful for those who have isolated atrial fibrillation and choose to have surgical ablation (maze procedure).
During surgery, the surgeon can either remove the LAA and sew the area closed or use a special device called the AtriClip*. The AtriClip is implanted from the outside of the heart and stops the flow of blood between the LAA and the left atrium.
*Disclosure: Note that Cleveland Clinic has the potential to receive a royalty payment as a result of sale of the clip.
If you would like to be evaluated to see if surgical closure of the LAA is the best treatment option for you, Cleveland Clinic surgeons will review your records.
Amplatzer has made devices to close holes in the septum of the heart (a congenital heart problem) for some time. Similar to the other devices, a catheter is inserted through a vein at the groin and advanced across the septum to the LAA. The Amplatzer Cardiac Plug device is inserted into the opening of the LAA. This seals off the LAA and keeps it from releasing clots.
The device has been used in Europe since 2008 and is currently being tested in the United States for safety and efficacy.
To learn more about the WATCHMAN Device, visit the following sites: