The left anterior descending artery (also LAD, anterior interventricular branch of left coronary artery, or anterior descending branch) is a branch of the
left coronary artery.
Blockage
''Blockage'' (Persian: سد معبر, romanized: Sade Ma'bar) is a 2017 Iranian drama film directed by Mohsen Gharaie and written by Saeed Roustayi. The film screened for the first time at the 35th Fajr Film Festival and received 4 nominations.
I ...
of this artery is often called the ''widow-maker infarction'' due to a high death risk.
Structure
It passes at first behind the
pulmonary artery and then comes forward between that vessel and the
left atrium to reach the
anterior interventricular sulcus, along which it descends to the
notch of cardiac apex.
Although rare, multiple anomalous courses of the LAD have been described. These include the origin of the artery from the right
aortic sinus.
In 78% of cases, it reaches the
apex of the heart.
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 anterior 2/3 of the
interventricular septum.
* Diagonals run along the surface of the heart and supply the lateral wall of the
left ventricle and the anterolateral
papillary muscle.
Segments
* Proximal: from LAD origin to, and including, the origin of the first septal branch
(some definitions say to first diagonal, or to whichever comes first)
* Middle: from proximal segment to halfway of remaining distance to apex.
A more technical definition is from the proximal segment to the point where the LAD forms an angle, as seen from a right anterior oblique view on
angiography, which is often close to the origin of the second diagonal branch.
* Distal: from middle segment to apex,
or in some cases beyond.
Function
The artery supplies the anterolateral
myocardium
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that ...
, apex, and
interventricular septum. The LAD typically supplies 45–55% of the
left ventricle (LV) and is therefore considered the most critical vessel in terms of myocardial blood supply.
Widow maker
''Widow maker'' is an alternative name for the anterior interventricular branch of the
left coronary artery.
The name ''widow maker'' may also apply to the left coronary artery
or severe occlusions to that artery.
This term is used because the left main coronary and/or the left anterior descending supply blood to large areas of the heart. This means that if these arteries are abruptly and completely occluded it will cause a massive
heart attack that will likely lead to sudden death. The blockage that kills is made up of
platelets
Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...
streaming to the site of a ruptured cholesterol plaque. Even a small amount of plaque in this area can (for a variety of poorly understood reasons) rupture and cause death;
bypassing chronic blockages or trying to open them up with
angioplasty does not prevent heart attack but it can restore blood flow in case of a sudden blockage or heart attack and if performed within a rapid time period can minimize the damage done. An example of the devastating results of a complete occlusion of the LAD artery was the sudden death of former NBC News Washington Bureau Chief
Tim Russert,
as well as the near-death of film director
Kevin Smith.
From the minute a widow maker heart attack hits, survival time ranges from minutes to several hours. Rapidly progressing symptoms should signal the need for immediate attention. Symptoms of initial onset may include nausea, shortness of breath, pain in the head, jaw, arms or chest, numbness in fingers, often of a novel but imprecise sensation which builds with irregular heart beat. Early symptoms may be mistaken for food poisoning, flu or general malaise until they intensify. A widow maker cannot kill instantly but induces cardiac arrest which may do so within 10 to 20 minutes of no circulation. A victim with no pulse or breath is still alive, living off oxygen stored in the blood and may be able to be rescued if treatment is begun promptly within this window.
Additional images
Image:Coronary arteries.svg, Coronary arteries (labeled in red text)
Image:Gray505.png, The arch of the aorta, and its branches.
Image:Heart attack diagram.png, Heart attack
Image:Cardiac vessels.png, Cardiac vessels
Image:Human heart with coronary arteries new.png, Human heart with coronary arteries
Image:Heart coronary territories.jpg, Heart coronary territories
References
External links
* - "Heart: The Left Coronary Artery and its Branches"
* - "Anterior view of the heart."
{{Authority control
Arteries of the thorax