Left Coronary Artery Flashcards
Left Main
Frist brach of left coronary. Not everyone has one. some are short and some are longer. Can bifrication occur right after. Some people do not have one. Just have LAD and Cx.
Two main branches off of LCA
LAD and Cx
What are the vessels that come off of the LAD
Diagonals and Septal perforators
What are diagonals
The LAD gives off several diagonal branches. These run diagonally on the anterolateral portion of the left ventricle. The first diagonal branch is designated as D1; the second diagonal branch is designated as D2; and so on. Generally not more than 4. About 4 , 3 or 2.
What are septal perforators
Septal perforators are branches of the left anterior descending (LAD) artery that supply blood to the interventricular septum of the heart. A lot more septals than diagonals
RCA
The right coronary artery (RCA) has three sections: proximal, middle, and distal.
**Proximal segment **
Starts at the origin of the RCA
Runs horizontally for about 15–25 mm
Extends to the acute marginal branch
Gives rise to the conus and sinoatrial branches
**Middle segment **
Runs from the proximal segment to the acute margin
Courses along the posterior AV groove
**Distal segment **
Runs from the acute margin to the origin of the posterior interventricular artery
Courses along the posterior interventricular sulcus
The RCA supplies blood to the right side of the heart and the back wall of the left side. It has many branches, including:
Conus artery: Supplies blood to the right ventricle and the arteries that go to the lungs
**Sinoatrial nodal branch: **Supplies blood to the sinoatrial node, which controls the heart’s electrical impulses
Right acute marginal branch: Supplies blood to the right ventricle
Posterior interventricular branch: Also known as the posterior descending artery (PDA)
Posterolateral branch: Branches from the RCA in about 70% of people
LAD
The left anterior descending (LAD) artery has three main sections: proximal, mid, and distal. The LAD also has two types of branches: septal and diagonal.
Sections of the LAD
** Proximal LAD: T**he section of the LAD between the LAD’s origin and the origin of the first diagonal branch (D1)
**Mid-LAD: **The section of the LAD between the proximal LAD and the distal LAD
**Distal LAD: **The most distal third of the LAD
Branches of the LAD
Septal branches
These branches supply blood to the front two-thirds of the septum. They originate from the LAD at a 90 degree angle to the heart’s surface.
Diagonal branches
These branches supply blood to the front and bottom of the heart’s lower left ventricle. They run along the surface of the heart and branch off at acute angles.
The LAD is the largest coronary artery in the heart. It runs from the base of the heart to the apex. A blockage in the LAD can lead to a widowmaker heart attack.
What is Cx
The circumflex artery (Cx) is a coronary artery that supplies blood to the back and side of the heart. It branches off from the left coronary artery and wraps around the heart.
Function:
Supplies blood to the left atrium, the back and lateral walls of the left ventricle, and part of the anterior papillary muscle
Helps form the posterior left ventricular branch, or posterolateral artery
**Signs of blockage: **
Chest pain or pressure (angina)
Cold sweats or clamminess
Dizziness or feeling lightheaded
Fatigue and weakness
Heart palpitations
Nausea
Shortness of breath
Shoulder or arm pain
Neck or jaw pain
Other notes:
-The circumflex artery contains obtuse marginal arteries, which supply the lateral left ventricular wall
-The circumflex artery travels in the left AV groove between the left atrium and left ventricle
-A significant narrowing of the circumflex artery can lead to worse outcomes than right coronary artery narrowing
-The circumflex artery is sometimes called the “circ”
Non-dominant Cx
A “non-dominant Cx” in the heart refers to a situation where the left circumflex coronary artery (Cx) is not the primary blood supplier to the inferior wall of the heart, meaning it is not the dominant coronary artery, which usually happens when the right coronary artery supplies the majority of blood to that area instead; essentially, a “non-dominant Cx” indicates that the circumflex artery is not the main vessel supplying blood to the posterior part of the heart.
Key points about non-dominant Cx:
Coronary dominance:
The “dominant” coronary artery is the one that supplies the majority of blood to the inferior wall of the heart, usually determined by which vessel gives rise to the posterior descending artery.
Most common scenario:
In most people, the right coronary artery (RCA) is the dominant coronary artery, making the left circumflex (Cx) a “non-dominant” vessel.
Clinical implications:
While a non-dominant Cx is usually not problematic, if there is a significant blockage in the circumflex artery, it can lead to reduced blood flow to the affected area of the heart, potentially causing symptoms like chest pain
ramus intermedius
The ramus intermedius (RI) is a coronary artery that branches off from the left main coronary artery (LMCA). It’s a normal variant that occurs in about 15–30% of people. Needs to be trification.
Function:
Supplies blood to the lateral wall of the heart
Has a similar course and perfusion region to the obtuse marginal branches of the left circumflex artery
**Significance: **
Can increase the risk of atherosclerotic plaque formation
Can be diagnosed using coronary computed tomography angiography (CTA)
If occluded, can cause chest pain, increased troponin levels, and electrocardiographic changes
**Anatomy: **
Slides over the free surface of the left ventricle instead of running along an anatomical groove
Can have a course similar to the diagonal branches of the left anterior descending artery
**Treatment: **
Percutaneous coronary intervention (PCI) with stent implantation can be an alternative to coronary artery bypass grafting (CABG)
