left atrial appendage (LAA)

The left atrial appendage (LAA) is a small, ear-shaped pouch located in the upper left chamber of the heart, called the left atrium. Its primary function isn’t fully understood, but it plays a role in blood flow regulation. In people with atrial fibrillation—a common heart rhythm disorder—the LAA can become a site where blood clots form. These clots may travel to the brain, causing strokes. Because of this risk, doctors sometimes remove or seal off the LAA to reduce stroke chances while managing atrial fibrillation.