Atrial Fibrillation Video Series: Day Twelve
The Left Atrial Appendage: A Small Pocket with Big Importance
Throughout this series, we’ve talked about the left atrial appendage (LAA) a few times, especially when discussing stroke risk and treatments like blood thinners or surgical ablation. Now, let’s give the LAA the spotlight for a moment. What exactly is this appendage, and why does it matter so much in atrial fibrillation?
The left atrial appendage is a little pouch or outpouching off the left atrium (one of the heart’s upper chambers). In people without AF, it’s a quiet, unremarkable part of the heart – blood flows in and out of it with each heartbeat, and it doesn’t cause any trouble. In fact, its original purpose is not entirely clear, but it might help regulate pressure or be a leftover from our development in the womb. However, in AF, the LAA becomes significant because blood can stagnate there when the atria are not contracting properly. As we know, stagnant blood can form clots, and clots in the LAA can escape and cause strokes. It’s estimated that in non-valvular AF (AF not due to a mechanical heart valve or rheumatic disease), over 90% of stroke-causing clots originate from the LAA. That’s why it’s often called the “usual suspect” in AF-related strokes.
The primary strategy to deal with LAA clots has been blood thinners (anticoagulants, which we discussed). These medications don’t remove clots that are already there, but they help prevent new clots from forming by altering the blood’s clotting ability. But what if someone can’t take blood thinners, or we want to secure protection without lifelong medication? That’s where LAA closure or removal comes into play.
There are a couple of approaches:
- Catheter-based devices: You might have heard of the Watchman device (one example of an LAA occlusion device). In this procedure, a cardiologist uses a catheter (through the vein, into the heart) to deploy a tiny umbrella- or plug-like device that sits in the mouth of the appendage, sealing it off from the inside. Over time, heart tissue grows over the device, permanently closing off the appendage so clots can’t escape. This is done under general anesthesia but is not open surgery. It’s a relatively common procedure now for AF patients who need an alternative to blood thinners.
- Surgical closure or removal: If you’re undergoing heart surgery for any reason (valve surgery, bypass, or a surgical AF ablation like we discussed), the surgeon can take the opportunity to address the LAA. This can be done by sewing it closed, cutting it out, or placing a clip on it from the outside. The surgical clip (often an item called the AtriClip) can close the appendage off securely. These surgical options are very effective and can be done as part of the main operation so you don’t even really notice an extra “procedure” from the patient’s perspective .
By neutralizing the appendage (closing or removing it), we dramatically reduce the risk of stroke from AF without needing ongoing anticoagulation in some cases. It’s important to note, though, that doctors will usually still have you on blood thinners for a short period after an appendage closure device until it’s well sealed, and even long-term if you have other reasons for stroke risk. The decision to stop blood thinners after an LAA closure is individualized and made by your cardiologist based on follow-up tests (like a special heart ultrasound called a TEE to check the device).
For many patients, knowing the LAA can be “dealt with” is reassuring. If you’re someone who cannot tolerate blood thinners due to bleeding issues or have a lifestyle that makes them risky (for example, frequent falls or high bleeding risk), an LAA closure might be a lifesaver by allowing protection against stroke without the daily medication.
In summary, the left atrial appendage might be small, but in AF it’s a big troublemaker when it comes to strokes. Thankfully, we have ways to disarm this little pocket – either by medication or by physically closing it off. If your doctor mentions the appendage in your treatment plan, you’ll now know why it’s such a focal point of AF management.
Next email: Many people with AF also happen to need heart surgery for other reasons, like a valve problem. We’ll discuss how AF is addressed during heart valve surgery and why it’s a great idea to tackle both issues together when possible.
