Left auricular appendix
Encyclopedia
The left atrial appendage (LAA) (left auricular appendix, auricula, left auricle) is a muscular pouch connected to the left atrium
of the heart
.
It has a distinct embryologic origin.
.
, blood clots arise from the left atrial appendage in more than 90% of cases. They may dislodge (forming emboli), which may lead to ischemic
damage to the brain, kidneys, or other organs supplied by the systemic circulation. Left atrial appendage occlusion
is an experimental treatment to prevent stroke
in atrial fibrillation
.
It can serve as an approach for mitral valve
surgery.
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
.
It has a distinct embryologic origin.
Terminology
Although the LAA is sometimes called the left auricle, in older texts the term "left auricle" was often used differently to describe the structure now known as the left atriumLeft atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
.
Clinical significance
In atrial fibrillationAtrial fibrillation
Atrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
, blood clots arise from the left atrial appendage in more than 90% of cases. They may dislodge (forming emboli), which may lead to ischemic
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
damage to the brain, kidneys, or other organs supplied by the systemic circulation. Left atrial appendage occlusion
Left atrial appendage occlusion
Left atrial appendage occlusion is a treatment strategy to prevent blood clot formation in atrial fibrillation . In this heart rhythm disorder, blood clots form in the left atrial appendage in 90% of cases....
is an experimental treatment to prevent stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
in atrial fibrillation
Atrial fibrillation
Atrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
.
It can serve as an approach for mitral valve
Mitral valve
The mitral valve is a dual-flap valve in the heart that lies between the left atrium and the left ventricle...
surgery.