Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia. AF is often caused by changes in the heart that occur as a result of heart disease, high blood pressure, and aging. Episodes of atrial fibrillation can come and go, called paroxysmal AF, or the condition may be chronic.
During atrial fibrillation, the heart’s two upper chambers (the atria) beat rapidly and irregularly (fibrillate). No effective atrial contraction occurs, which disturbs the normal blood flow through the heart. It commonly causes symptoms of heart palpitations, shortness of breath, weakness and fatigue.
Left Atrial Appendage
The left atrial appendage (LAA) is a muscular pouch connected to the left atrium of the heart. It differs from the atrium in structure, function, and activity. It is a thin-walled structure that expands to help control LA volume. The existence of the LAA in humans is universal. The shape of the appendage differs from person to person. Atrial fibrillation causes the blood flow to slow and sometimes stop altogether in this pouch.
The combination of slow blood flow and the structure of the LAA can cause blood clots to form. These clots can then break off (embolize) and travel to the brain and other organs.