How Does LAA Closure for Atrial Fibrillation Affect Heart Pumping Ability?

Left Arial Appendage (LAA) closure is the cornerstone of stroke prevention in surgical treatment of A-Fib. The Left Atrial Appendage is closed off, cut out, stapled shut, or shut off with a clip. How does this affect the heart’s ability to pump blood?

Small Study to Directly Measure Pumping Effect of LAA Closure

In a very small study of the hybrid operation/ablation, seven patients were measured for cardiac output and left ventricular stroke volume just before the hybrid operation, directly after, then ten minutes later.

The researchers pointed out that “the LAA also has a contractile function and takes part in the LA contraction process, especially in patients in SR (sinus rhythm)”.

But five of the seven patients were in A-Fib and already had reduced ejection fraction (EF) (26%). (Normal EF is 50% to 75%.) Even in the patients in SR, their EF was only 46%.

Ejection fraction (EF) is a percentage of blood that is pumped out of the heart during each beat. A range of 50%-75% indicates your heart is pumping well, delivering an adequate amount of blood to the body and brain.

LAA Closure Lowers Pumping Pressure Long Term

The researchers pointed out that LAA closure “can result in lower systolic blood pressure on the long term” according to previous research. (“Systolic” is the top number in your blood pressure measurement and is the pumping force your heart exerts.)

The researchers also pointed out that the LAA is the predominant site of atrial natriuretic peptide (ANP) in the heart which can affect heart pumping “volume overload”.

No Significant Difference

The researchers found no significant differences in various pumping measurements, but the Left Ventricular Stroke Volume (LSCI) was affected (28 mLm² to 24 mLm², P-value 0.066).

Editor’s Comments

Patients with Poor EF: In patients with poor heart pumping and contracting ability (EF below 50%) to begin with, this study suggests they aren’t affected much by losing their LAA. They probably wouldn’t even notice it was gone. But the jury is still out on how losing the LAA affects even A-Fib patients with poor Ejection Fraction (EF) long term.

Patients with Normal EF: However, this may not be the case with A-Fib patients with a normal EF. The LAA does have a contractile function, particularly in patients with larger size LAAs. (Do athletes have larger size LAAs due to their exercise?)  This small study did not address the cases of A-Fib patients with normal EFs.

What This Means for A-Fib Patients

This small study didn’t measure patients with a normal Ejection Fraction (EF) who had their Left Atrial Appendage (LAA) closed off or removed. Most likely the heart’s pumping ability is affected by losing one’s LAA. (In dogs, the LAA provides 17.2% of the volume of blood pumped by the left atrium.)

If you are an active exerciser or athlete, you may want to consider keeping your LAA if possible. But for most people, losing your LAA probably won’t affect you very much. You may not even notice your LAA is gone.

What this Means to Me: A Watchman in my Future

Personally, I love to run, do sprints, etc. But after two recent ablations (after 21 years of being A-Fib free), my Medtronic Reveal LINQ loop recorder recently picked up a full day of Silent A-Fib signals. (Reports are sent wirelessly to my EP each night by the bedside transmitter.)

This wasn’t a big surprise. In my last ablation, my LAA was ablated to stop A-Fib signals, but it also electrically affected the LAA from pumping out properly. My EPs warned me that I would likely need to close-off my LAA sometime in the future.

With this recent data, my two EPs (Drs. Doshi and Natale) recommended I close-off my LAA with a Watchman device.

Even though it might affect my pumping ability, at age 81, stopping my A-Fib signals is more important to me. After my Watchman implant, I’ll write more. 

For my first-hand account of having a Medtronic Reveal LINQ loop recorder, go to Has My A-Fib Returned? I Get an Insertable Wireless Monitor

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