Left main coronary artery. Coronary arteries of the heart, diagram of vessels

The LCA supplies blood to a much larger array of the heart, both in volume and in value. However, it is customary to consider what type of blood supply (left vein, right vein or uniform) is present in the patient. It's about about which artery in a particular case formed the posterior interventricular artery, the blood supply zone of which is the posterior third interventricular septum; that is, in the presence of the right coronary type, the posterior interventricular branch is formed from the RCA, which is more pronounced than the envelope branch of the LCA. However, this does not mean that the RCA supplies blood to a larger array of the heart compared to the LCA. The right coronary type of vascularization is characterized by the fact that the right coronary artery extends beyond the posterior longitudinal sulcus and supplies the right and most of the left heart with its branches, and the circumflex branch of the left coronary artery ends at the blunt edge of the heart. With the left coronary type, the circumflex branch of the left coronary artery extends beyond the posterior longitudinal groove, giving off the posterior interventricular branch, which usually departs from the right coronary artery and supplies with its branches not only the posterior surface of the left heart, but also most of the right one, and the right coronary artery ends on a sharp edge hearts. With a uniform type of blood supply to the heart, both coronary arteries are equally developed. Some authors, in addition to these three types of blood supply to the heart, distinguish two more intermediate ones, designating them "middle right" and "middle left".

The predominance of the right coronary artery of the heart is noted only in 12% of cases, in 54% of cases the left coronary artery predominates, and in 34% both arteries are developed evenly. With the dominance of the right coronary artery, there is never such a sharp difference in the development of both coronary arteries, which is observed in the left coronary type. This is due to the fact that the anterior interventricular branch, always formed by the left coronary artery, supplies blood to significant areas of the LV and RV.

coronary arteries and their branches, located subepicardially, are surrounded by loose connective tissue, which increases with age. One of the features of the topography of the coronary arteries is the presence of muscle bridges in the form of bridges or loops above them in 85% of cases. Muscular bridges are part of the myocardium of the ventricles and are more often detected in the anterior interventricular sulcus above the sections of the same-named branch of the left coronary artery. The thickness of the muscle bridges is in the range of 2-5 mm, their width along the course of the arteries varies in the range of 3-69 mm. In the presence of bridges, the artery has a significant intramural segment and acquires a "diving" course. During intravital coronary angiography, their presence is detected in systole by a conical narrowing of the artery or its sharp bend in front of the bridge, as well as insufficient filling of the vessel under the bridge. In diastole said changes disappear.

Additional sources of blood supply to the heart include internal thoracic, superior phrenic, intercostal arteries, bronchial, esophageal and mediastinal branches of the thoracic aorta. From the branches of the inner thoracic arteries the pericardial-phrenic arteries matter. The second leading source of additional vascularization of the heart is the bronchial arteries. The average total cross-sectional area of all extracardiac anastomoses at the age of 36-55 years and older than 56 years is 1.176 mm2.

V.V. Bratus, A.S. Gavrish "Structure and functions of the cardiovascular system"

Anatomy coronary circulation highly variable. Features of the coronary circulation of each person are unique, like fingerprints, therefore, each myocardial infarction is "individual". The depth and prevalence of a heart attack depend on the interweaving of many factors, in particular on congenital anatomical features coronary bed, the degree of development of collaterals, the severity of atherosclerotic lesions, the presence of "prodromes" in the form of angina pectoris, which first appeared during the days preceding the infarction (ischemic "training" of the myocardium), spontaneous or iatrogenic reperfusion, etc.

As is known, heart receives blood from two coronary (coronary) arteries: the right coronary artery and the left coronary artery [respectively a. coronaria sinistra and left coronary artery (LCA)]. These are the first branches of the aorta that depart from its right and left sinuses.

Barrel LKA[in English - left main coronary artery (LMCA)] departs from the upper part of the left aortic sinus and goes behind the pulmonary trunk. The diameter of the LCA trunk is from 3 to 6 mm, the length is up to 10 mm. Usually the trunk of the LCA is divided into two branches: the anterior interventricular branch (AMV) and the circumflex (Fig. 4.11). In 1/3 of cases, the LCA trunk is divided not into two, but into three vessels: the anterior interventricular, circumflex, and median (intermediate) branches. In this case, the median branch (ramus medianus) is located between the anterior interventricular and envelope branches of the LCA.
This vessel- analogue of the first diagonal branch (see below) and usually supplies the anterolateral sections of the left ventricle.

Anterior interventricular (descending) branch of the LCA follows the anterior interventricular sulcus (sulcus interventricularis anterior) towards the apex of the heart. In English literature, this vessel is called the left anterior descending artery: left anterior descending artery (LAD). We will adhere to the more accurate anatomically (F. H. Netter, 1987) and the term "anterior interventricular branch" accepted in the domestic literature (O. V. Fedotov et al., 1985; S. S. Mikhailov, 1987). At the same time, when describing coronarograms, it is better to use the term "anterior interventricular artery" to simplify the name of its branches.

main branches latest- septal (penetrating, septal) and diagonal. The septal branches depart from the PMA at a right angle and deepen into the thickness of the interventricular septum, where they anastomose with similar branches extending from below the posterior interventricular branch of the right coronary artery (RCA). These branches may differ in number, length, direction. Sometimes there is a large first septal branch (going either vertically or horizontally - as if parallel to the PMA), from which branches extend to the septum. Note that of all areas of the heart, the interventricular septum of the heart has the thickest vascular network. The diagonal branches of the PMA run along the anterolateral surface of the heart, which they supply with blood. There are from one to three such branches.

In 3/4 cases of PMV does not end in the region of the apex, but, bending around the latter on the right, wraps itself on the diaphragmatic surface of the posterior wall of the left ventricle, supplying both the apex and partially the posterior diaphragmatic sections of the left ventricle, respectively. This explains the appearance of the Q wave on the ECG in lead aVF in a patient with extensive anterior infarction. In other cases, ending at the level or not reaching the apex of the heart, PMA does not play a significant role in its blood supply. Then the apex receives blood from the posterior interventricular branch of the RCA.

proximal area front The interventricular branch (PMV) of the LCA is called the segment from the mouth of this branch to the origin of the first septal (penetrating, septal) branch or to the origin of the first diagonal branch (less stringent criterion). Accordingly, the middle section is a segment of the PMA from the end of the proximal section to the departure of the second or third diagonal branch. Next is the distal section of the PMA. When there is only one diagonal branch, the boundaries of the middle and distal sections are determined approximately.

Educational video of the blood supply of the heart (anatomy of arteries and veins)

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The arteries of the heart depart from the aortic bulb - the initial expanded section of the ascending aorta and, like a crown, surround the heart, in connection with which they are called coronary arteries. The right coronary artery begins at the level of the right sinus of the aorta, and the left coronary artery - at the level of its left sinus. Both arteries depart from the aorta below the free (upper) edges of the semilunar valves, therefore, during contraction (systole) of the ventricles, the valves cover the openings of the arteries and almost do not let blood flow to the heart. With relaxation (diastole) of the ventricles, the sinuses fill with blood, blocking its path from the aorta back to the left ventricle, and at the same time open the access of blood to the vessels of the heart.

Right coronary artery

It leaves to the right under the ear of the right atrium, lies in the coronary sulcus, goes around the right pulmonary surface of the heart, then follows its posterior surface to the left, where it anastomoses with its end with the circumflex branch of the left coronary artery. Most large branch The right coronary artery is the posterior interventricular branch, which is directed along the sulcus of the same name towards the apex of the heart. Branches of the right coronary artery supply the wall of the right ventricle and atrium. back interventricular septum, papillary muscles of the right ventricle, posterior papillary muscle of the left ventricle, sinoatrial and atrioventricular nodes of the conduction system of the heart.

Left coronary artery

A little thicker than the right. Between the start pulmonary trunk and the auricle of the left atrium, it is divided into two branches: the anterior interventricular branch and the circumflex branch. The latter, which is a continuation of the main trunk of the coronary artery, goes around the heart on the left, located in its coronary sulcus, where it anastomoses with the right coronary artery on the posterior surface of the organ. The anterior interventricular branch follows the sulcus of the same name towards the apex of the heart. In the region of the cardiac notch, it sometimes passes to the diaphragmatic surface of the heart, where it anastomoses with the terminal section of the posterior interventricular branch of the right coronary artery. The branches of the left coronary artery supply the wall of the left ventricle, including the papillary muscles, most of the interventricular septum, the anterior wall of the right ventricle, and the wall of the left atrium.

The branches of the right and left coronary arteries, connecting, form two arterial rings in the heart: a transverse one, located in the coronary sulcus, and a longitudinal one, the vessels of which are located in the anterior and posterior interventricular sulci.

Branches of the coronary arteries provide blood supply to all layers of the walls of the heart. In the myocardium, where the level of oxidative processes is the highest, microvessels anastomosing with each other repeat the course of the bundles of muscle fibers of its layers.

There are various options for the distribution of branches of the coronary arteries, which are called types of blood supply to the heart. The main ones are as follows: right coronary, when most parts of the heart are supplied with blood by the branches of the right coronary artery; left coronary, when most of the heart receives blood from the branches of the left coronary artery, and medium, or uniform, in which both coronary arteries evenly participate in the blood supply to the walls of the heart. There are also transitional types of blood supply to the heart - middle right and middle left. It is generally accepted that among all types of blood supply to the heart, the middle right type is predominant.

Variants and anomalies of the position and branching of the coronary arteries are possible. They are manifested in changes in the places of origin and the number of coronary arteries. So, the latter can depart from the aopta directly above the semilunar valves or much higher - from the left subclavian artery and not from the aorta. The coronary artery may be the only one, that is, unpaired, there may be 3-4 coronary arteries, and not two: two arteries depart to the right and left of the aorta, or two from the aorta and two from the left subclavian artery.

Along with the coronary arteries, non-permanent (additional) arteries go to the heart (especially to the pericardium). These can be mediastinal-pericardial branches (upper, middle and lower) of the internal thoracic artery, branches of the pericardial phrenic artery, branches extending from the concave surface of the aortic arches, etc.

coronary arteries are the vessels that supply the heart muscle necessary nutrition. Pathologies of these vessels are very common. They are considered one of the main causes of death in the elderly.

The scheme of the coronary arteries of the heart is branched. The network includes large branches and great amount small vessels.

The branches of the arteries originate from the aortic bulbs and go around the heart, providing an adequate supply of blood. different areas hearts.

Vessels consist of endothelium, muscular fibrous layer, adventitia. Due to the presence of such a number of layers, the arteries differ high strength and elasticity. This allows blood to move normally through the vessels even if the load on the heart is increased. For example, during training, when athletes' blood moves five times faster.

Types of coronary arteries

All arterial network comprises:

main vessels;
adnexal.

The last group includes such coronary arteries:

Right. She is responsible for the flow of blood to the cavity of the right ventricle and the septum.
Left. From her blood comes to all departments. It is divided into several parts.
bending branch. It departs from the left side and provides nutrition to the septum between the ventricles.
Anterior descending. Thanks to it, nutrients enter different parts of the heart muscle.
Subendocardial. They pass deep into the myocardium, and not on its surface.

The first four views are located on top of the heart.

Types of blood flow to the heart

There are several options for blood flow to the heart:

Right. It is the dominant species if this branch originates from right artery.
Left. This method of nutrition is possible if the posterior artery is a branch of the circumflex vessel.
Balanced. This type is isolated if blood flows simultaneously from the left and right arteries.

Most people have the right type of blood supply.

Possible pathologies

The coronary arteries are blood vessels that provide vital important organ enough oxygen and nutrients. The pathologies of this system are considered one of the most dangerous, as they gradually lead to more serious illnesses.

angina pectoris

The disease is characterized by attacks of suffocation with severe pain in the chest. This condition develops when the vessels are affected by atherosclerosis and the heart does not receive enough blood.

Pain is associated with oxygen starvation heart muscle. Physical and mental stress, stress and overeating aggravate the symptoms.

myocardial infarction

This dangerous problem in which certain parts of the heart die. The condition develops when the blood supply stops completely. This usually occurs when the coronary arteries of the heart are clogged with a blood clot. Pathology has vivid manifestations:

The area that was subject to necrosis can no longer contract, but the rest of the heart works as before. Because of this, the damaged area may rupture. Lack of medical assistance will lead to the death of the patient.

Causes of defeat

Damage to the coronary arteries in most cases is associated with insufficient attention to the state of one's own health.

Every year similar violations lead to the deaths of millions of people around the world. At the same time, most people are residents of developed countries and are well off.

The provoking factors contributing to violations are:

An equally important influence age-related changes, hereditary predisposition, gender. Such diseases are acute form affect men, so they die from them much more often. Women are more protected due to the influence of estrogen, so they are more likely to chronic course.

circumflex branch of the left coronary artery begins at the site of bifurcation (trifurcation) of the LCA trunk and goes along the left atrioventricular (coronal) sulcus. The circumflex branch of the LCA will be referred to hereinafter for simplicity as the left circumflex artery. By the way, this is exactly what it is called in English-language literature - left circumflex artery (LCx).

From circumflex artery depart from one to three large (left) marginal branches running along the blunt (left) edge of the heart. These are its main branches. They supply blood to the lateral wall of the left ventricle. After the departure of the marginal branches, the diameter of the circumflex artery decreases significantly. Sometimes only the first branch is called the (left) marginal, and the subsequent ones are called (posterior) lateral branches.

circumflex artery also gives from one to two branches going to the lateral and posterior surfaces of the left atrium (the so-called anterior branches to the left atrium: anastomotic and intermediate). In 15% of cases, with a left-(non-right-) coronary form of blood supply to the heart, the circumflex artery gives off branches to the posterior surface of the left ventricle or posterior branches of the left ventricle (F. H. Netter, 1987). In approximately 7.5% of cases, the posterior interventricular branch also departs from it, feeding both the posterior part of the interventricular septum and partially the posterior wall of the right ventricle (J. A. Bittl, D. C. Levin, 1997).

Proximal section of the envelope branch of the LCA call the segment from its mouth to the departure of the first marginal branch. There are usually two or three marginal branches to the left (blunt) edge of the heart. Between them is middle part envelope branch of the LCA. The last marginal, or as it is sometimes called (posterior) lateral, branch is followed by the distal section of the circumflex artery.

Right coronary artery

In their initial departments the right coronary artery (RCA) is partially covered by the right ear and follows the right atrioventricular sulcus (sulcus coronarius) in the direction of the decussation (the place on the diaphragmatic wall of the heart where the right and left atrioventricular sulci converge, as well as the posterior interventricular sulcus of the heart (sulcus interventricularis posterior)) .

first branch, outgoing from the right coronary artery is a branch to the arterial cone (in half of the cases it departs directly from the right coronary sinus of the aorta). When blocking the anterior interventricular branch of the LCA, the branch to the arterial cone is involved in maintaining collateral circulation.

The second branch of the PCA is a branch to sinus node(in 40-50% of cases, it can depart from the envelope branch of the LCA). Departing from the RCA, the branch to the sinus angle is directed posteriorly, supplying blood not only to the sinus node, but also right atrium(sometimes both atria). The branch to the sinus node goes in the opposite direction with respect to the branch of the arterial cone.

Next branch is a branch to the right ventricle (may be up to three branches running parallel), which supplies blood to the anterior surface of the right ventricle. In its middle part, just above the sharp (right) edge of the heart, the RCA gives rise to one or more (right) marginal branches running towards the apex of the heart. They supply blood to both the anterior and back wall right ventricle, and also provide collateral blood flow with blockage of the anterior interventricular branch of the LCA.

Continuing to follow along the right atrioventricular sulcus, RCA goes around the heart and already on its posterior surface (almost reaching the intersection of all three sulci of the heart () gives rise to the posterior interventricular (descending) branch. The latter descends along the posterior interventricular sulcus, giving, in turn, the beginning of small lower septal branches , blood supply lower part septum, as well as branches to the posterior surface of the right ventricle. It should be noted that the anatomy of the distal RCA is very variable: in 10% of cases there may be, for example, two posterior interventricular branches running parallel.

Proximal section of the right coronary artery call the segment from its beginning to the branch to the right ventricle. The last and lowest outgoing (if there is more than one) marginal branch is limited middle department PCA. This is followed by the distal portion of the RCA. In the right oblique projection, the first - horizontal, second - vertical and third - horizontal segments of the RCA are also distinguished.

Educational video of the blood supply of the heart (anatomy of arteries and veins)

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