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Left Atrial Appendage Closure

Atrial fibrillation (also known as “AF” or “A-Fib”) is a type of irregular heart rhythm or arrhythmia that affects over 30 million people worldwide and is a leading cause of deadly strokes, particularly in the elderly.

With atrial fibrillation, the heart may not be able to pump blood normally. This can cause blood to pool in a small pouch that sits off the left side of the heart, known as the left atrial appendage (LAA), and form a clot. If left untreated, the clot can enter the bloodstream, travel to the brain and cause a stroke.

To reduce the risk of stroke, physicians often prescribe a blood-thinning medication, or anticoagulant. These medications slow down or prevent blood cells from clumping together to form a clot. But they may not be appropriate for everyone. Instead, a treatment called the Left Atrial Appendage Closure may be an alternative. Using a specialized implantable device, the procedure is designed to permanently seal off the appendage in the heart where blood clots can form.


How it works

In the minimally-invasive procedure, a specialized device is guided by a catheter through a vein in the upper leg and into the left side of the heart. Once in position, the implant is released and seals off the left atrial appendage. Over time, heart tissue grows over the device to create a permanent barrier. The procedure typically takes an hour, with only a 24-hour recovery time.

Dr. Sheldon Singh provides information on what to expect during a left atrial appendage closure:


Going home after getting a Left Atrial Appendage Occlusion Device


How we’re making a difference

An alternative to blood thinners

An implantable heart device to reduce the risk of stroke in patients with atrial fibrillation provides an alternative to the use of blood thinners. Read more »


Make an appointment

Referrals by a physician are required. To see if the Left Atrial Appendage Closure is an option for you, your cardiologist will need to send a referral to arrange for an assessment. You will then meet with a member of our care team to discuss if the procedure is right for you.

» Download our referral form


Join a study

Sunnybrook is participating in a research study to see the benefits of left atrial appendage occlusion with the Watchman device in addition to continuing blood thinners. Learn more »

Contact Us

Left Atrial Appendage Clinic
Sunnybrook Health Sciences Centre
2075 Bayview Avenue,
A-Wing, 2nd floor, room A222
Toronto, ON M4N 3M5

Phone: 416-480-6100 ext. 683659
Fax: 416-480-5707
Hours: Monday - Friday 8 a.m. - 4 p.m.

Dr. Sheldon Singh
Dr. Nicolas Bowers