The "LAD", or left anterior descending artery (or anterior interventricular branch of the left coronary artery

Left coronary artery

The left coronary artery, abbreviated LCA and also known as the left main coronary artery , arises from the aorta above the left cusp of the aortic valve.-Branching:...

, or anterior descending branch) is an artery

Artery

Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....

 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...

.

Course

It passes at first behind the pulmonary artery

Pulmonary artery

The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....

 and then comes forward between that vessel and the left auricula to reach the anterior interventricular sulcus, along which it descends to the incisura apicis cordis

Incisura apicis cordis

The anterior longitudinal sulcus and posterior longitudinal sulcus extend from the base of the ventricular portion to a notch, the incisura apicis cordis , on the acute margin of the heart just to the right of the apex....

.

In 78% of cases, it reaches the apex of the heart

Apex of the heart

The apex of the heart is the lowest superficial part of the heart.It is directed downward, forward, and to the left, and is overlapped by the left lung and pleura.-External anatomy:...

.

Supply

It supplies the anterolateral myocardium, apex, and interventricular septum

Interventricular septum

Interventricular septum , abbreviated IVS, is the stout wall separating the lower chambers of the heart from one another....

. The LAD typically supplies 45-55% of the left ventricle

Left ventricle

The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...

 (LV).

Branches

The LAD gives off two types of branches: septals and diagonals.

• Septals originate from the LAD at 90 degrees to the surface of the heart, perforating and supplying the interventricular septum
  Interventricular septum
  Interventricular septum , abbreviated IVS, is the stout wall separating the lower chambers of the heart from one another....
  
  .
• Diagonals run along the surface of the heart and supply the lateral wall of the left ventricle
  Left ventricle
  The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...
  
   and the anterolateral papillary muscle
  Papillary muscle
  In anatomy, the papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves via the chordae tendinae and contract to prevent inversion or prolapse of these valves.- Action :There are five total papillary muscles in the heart, three...
  
  .

"The Widowmaker"

Because the LAD provides much of the bloodflow for the left ventricle, which in turn provides much of the propulsive force for ejecting oxygenated blood to systemic circulation via the Aorta - blockage of this artery is particularly associated with mortality. In the medical community ischemic heart attacks associated with this blood vessel are colloquially called "the widowmaker."

Additional images

External links

- "Heart: The Left Coronary Artery and its Branches" - "Anterior view of the heart."