Cough

Circumflex branch. Anatomy of the coronary arteries: functions, structure and mechanism of blood supply

Anatomy of the coronary circulation highly variable. The 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 the congenital anatomical features of the 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 arise from its right and left sinuses.

LKA barrel[in English - left main coronary artery (LMCA)] arises from the upper part of the left aortic sinus and goes behind the pulmonary trunk. The diameter of the LKA trunk is from 3 to 6 mm, the length is up to 10 mm. Typically, the LCA trunk is divided into two branches: the anterior interventricular branch (AIV) and the circumflex branch (Fig. 4.11). In 1/3 of cases, the LMCA 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 circumflex branches of the LCA.
This vessel- analogous to the first diagonal branch (see below) and usually supplies the anterolateral parts of the left ventricle.

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

Main branches last- septal (penetrating, septal) and diagonal. The septal branches depart from the PMV at a right angle and deepen into the thickness of the interventricular septum, where they anastomose with similar branches arising inferiorly from 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 (running either vertically or horizontally - as if parallel to the PMV), from which branches extend to the septum. Note that of all regions of the heart, the interventricular septum of the heart has the densest vascular network. The diagonal branches of the PMV pass along the anterolateral surface of the heart, which they supply with blood. There are from one to three such branches.

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

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

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

If you have problems watching, download the video from the page

The coronary circulation circulates blood in the myocardium. The coronary arteries carry oxygenated blood to the heart according to a complex circulatory pattern, and the outflow of deoxygenated venous blood from the myocardium passes through the so-called coronary veins. There are superficial and small deep arteries. On the surface of the myocardium there are epicardial vessels, for which a characteristic feature is self-regulation, which allows maintaining optimal blood supply to the organ necessary for normal performance. Epicardial arteries have a small diameter, which often leads to atherosclerotic lesions and narrowing of the walls, followed by coronary insufficiency.

According to the diagram of the vessels of the heart, there are two main trunks of the coronary vessels:

right coronary artery – comes from the right aortic sinus, is responsible for blood supply to the right and posteroinferior wall of the left ventricle and some part of the interventricular septum;
left – comes from the left aortic sinus, then is divided into 2-3 small arteries (less often four); are considered the most significant anterior descending (anterior interventricular) and circumflex branches.

In each individual case, the anatomical structure of the heart vessels may vary, therefore, for a full study, cardiography of the heart vessels (coronary angiography) using an iodine-containing contrast agent is indicated.

Main branches right coronary artery: sinus node branch, conus branch, right ventricular branch, acute margin branch, posterior interventricular artery and posterolateral artery.

The left coronary artery begins with a trunk that divides into the anterior interventricular and circumflex arteries. Sometimes it goes between them intermediate artery (a.intermedia). Anterior interventricular artery(anterior descending) gives off diagonal and septal branches. Main branches circumflex artery are the branches of a blunt edge.

Types of myocardial blood circulation

Based on the blood supply to the posterior wall of the heart, balanced, left and right types of blood circulation are distinguished. Determination of the predominant type depends on whether one of the arteries reaches the avascular section, which was formed as a result of the intersection of two grooves - the coronary and interventricular. One of the arteries reaching this area gives off a branch that passes to the apex of the organ.

Therefore, the predominant right type of circulation The organ is provided by the right artery, which has a structure in the form of a large trunk, while the circumflex artery to this area is poorly developed.

Predominance left type accordingly, it assumes the predominant development of the left artery, which goes around the root of the heart and provides blood supply to the organ. In this case, the diameter of the right artery is quite small, and the vessel itself reaches only the middle of the right ventricle.

Balanced type assumes uniform blood flow to the above-mentioned area of the heart through both arteries.

Atherosclerotic lesion of heart vessels

Atherosclerotic disease of the heart and blood vessels is a dangerous lesion of the vascular walls, characterized by the formation of cholesterol plaques, which cause stenosis and prevent the normal flow of oxygen and nutrients to the heart. Symptoms of atherosclerosis of the heart vessels often manifest themselves in the form of angina attacks, leading to myocardial infarction, cardiosclerosis, as well as thinning of the vascular walls, which threatens their rupture and, without timely treatment, leads to disability or death.

How does IHD manifest itself?

The main cause of the development of coronary artery disease is atherosclerotic deposits on the vascular walls. Other causes of poor circulation include:

unhealthy diet (predominance of animal fats, fried and fatty foods);
age-related changes;
men are several times more likely to suffer from vascular diseases;
diabetes mellitus;
excess weight;
genetic predisposition;
persistent increase in blood pressure;
disturbed ratio of lipids in the blood (fat-like substances);
bad habits (smoking, drinking alcohol and drugs);
sedentary lifestyle.

Diagnostics of heart vessels

The most informative method for checking the vessels of the heart is angiography. Used to study coronary arteries selective coronary angiography of heart vessels- a procedure that allows you to assess the condition of the vascular system and determine the need for surgical intervention, but it has contraindications and in rare cases leads to negative consequences.

During the diagnostic study, a puncture is made in the femoral artery, through which a catheter is inserted into the vessels of the heart muscle to supply a contrast agent, resulting in an image being displayed on the monitor. Next, the area of narrowing of the artery walls is identified and its degree is calculated. This allows the specialist to predict the further development of the disease.

In Moscow, the prices of coronary angiography of the heart vessels on average vary from 20,000 to 50,000 rubles, for example, the Bakulev Center for Cardiovascular Surgery provides services for high-quality examination of the coronary vessels, the cost of the procedure starts from 30,000 rubles.

General methods of treating heart vessels

To treat and strengthen blood vessels, complex methods are used, consisting of dietary and lifestyle adjustments, drug therapy and surgical intervention.

adherence to dietary nutrition, with increased consumption of fresh vegetables, fruits and berries, which is useful for strengthening the heart and blood vessels;
light gymnastic exercises for the heart and blood vessels are prescribed at home, swimming, jogging and daily walks in the fresh air are recommended;
vitamin complexes are prescribed for the vessels of the brain and heart with a high content of retinol, ascorbic acid, tocopherol and thiamine;
droppers are used to support the heart and blood vessels, nourishing and restoring the structure of tissues and walls in the shortest possible time;
medications are used for the heart and blood vessels, reducing pain, removing cholesterol, lowering blood pressure;
a new technique for improving the activity of the heart and blood vessels is listening to therapeutic music: American scientists have proven a positive effect on the contractile function of the myocardium while listening to classical and instrumental music;
good results are observed after using traditional medicine: some medicinal plants have a strengthening and vitamin effect for the heart and blood vessels, the most popular are a decoction of hawthorn and motherwort.

Surgical methods for treating heart vessels

X-ray surgeons at work performing angioplasty and cardiac stenting

To improve blood circulation in the coronary arteries, balloon angioplasty and stenting are performed.

The balloon angioplasty method involves inserting a specialized instrument into the affected artery to inflate the vessel walls at the site of narrowing. The effect after the procedure remains temporary, since the operation does not involve eliminating the main cause of the stenosis.

For the most effective treatment of stenosis of the vascular walls, stents are installed in the vessels of the heart. A specialized frame is inserted into the affected area and expands the narrowed walls of the vessel, accordingly the blood supply to the myocardium improves. According to reviews of leading cardiac surgeons, after stenting of cardiac vessels, life expectancy increases, provided that all medical recommendations are followed.

The average cost of cardiac stenting in Moscow ranges from 25,000 to 55,000 rubles, excluding cost of tools; prices depend on many factors: the severity of the pathology, the number of stents and balloons required, the rehabilitation period, etc.

Circumflex branch of the left coronary artery begins at the site of bifurcation (trifurcation) of the left artery trunk and runs along the left atrioventricular (coronary) groove. For simplicity, we will further call the circumflex branch of the left artery the left circumflex artery. This is exactly what, by the way, it is called in English literature - left circumflex artery (LCx).

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

Circumflex artery It 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: anastomatic 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. S. Levin, 1997).

Proximal section of the circumflex branch of the LCA called the segment from its mouth to the origin of the first marginal branch. There are usually two or three marginal branches to the left (obtuse) edge of the heart. Between them is the middle part of the circumflex branch of the LCA. The last marginal, or as it is sometimes called (posterior) lateral, branch is followed by the distal portion 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 along the right atrioventricular groove (sulcus coronarius) towards the chiasm (the place on the diaphragmatic wall of the heart where the right and left atrioventricular grooves, as well as the posterior interventricular groove of the heart (sulcus interventricularis posterior) converge) .

The first branch outgoing from the right coronary artery - this is a branch to the conus arteriosus (in half of the cases it arises directly from the right coronary sinus of the aorta). When the anterior interventricular branch of the left artery is blocked, the branch to the conus arteriosus is involved in maintaining collateral circulation.

Second branch of PKA- this is a branch to the sinus node (in 40-50% of cases it can arise from the circumflex branch of the LCA). Departing from the RCA, the branch to the sinus angle goes posteriorly, supplying blood not only to the sinus node, but also to the right atrium (sometimes both atria). The branch to the sinus node goes in the opposite direction in relation to the branch of the conus arteriosus.

Next branch- this is a branch to the right ventricle (there can be up to three branches running in parallel), which supplies blood to the anterior surface of the right ventricle. In its middle part, just above the acute (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 posterior walls of the right ventricle, and also provide collateral blood flow during blockage of the anterior interventricular branch of the LCA.

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

Proximal section of the right coronary artery called the segment from its beginning to the branch leaving the right ventricle. The last and most inferior branch (if there is more than one) borders the middle part of the RCA. 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 blood supply to the heart (anatomy of arteries and veins)

If you have problems watching, download the video from the page

Rice. 50. Corrosive drug.

Posterior view of the coronary arteries and aortic orifice.

The non-coronary (non-facial) (N) sinus of the aorta is located strictly posteriorly. The right coronary artery (RCA) departs from the 1st facial sinus of the aorta (1), first in front of the tricuspid valve, and then, going around it, located posterior to it. The first major atrial branch of the SVA is the sinus node artery, which runs posterior to the aorta (shown by a white arrow). The left coronary artery (LCA) departs from the 2nd facial sinus of the aorta (2), giving off the circumflex and anterior interventricular branches (LAD). The black arrow shows the LAD, which supplies the apex and gives branches to the papillary muscles of both ventricles. The course of the LAD and the posterior interventricular branch (POIB) shows the divergence of the axes of the anterior and posterior interventricular septa of the heart. It can be seen that the anterior interventricular septum in the area of the cone is sharply deviated to the left.

WOK - a branch of a sharp edge.

Adventitial artery

The third permanent branch of the right VA is the adventitial artery. This small artery can be a branch of the conus artery or arise independently (see Fig. 28) from the aorta1 7. It goes up and to the right and lies on the anterior wall of the aorta (above the sinotubular junction), heading to the left and disappearing into the fatty sheath surrounding the great vessels.

It requires coagulation during aortic cannulation and during coronary artery bypass surgery, as it can be a source of bleeding.

Having given off these three branches, the right V A follows in the right atrioventricular groove and, going around the right edge of the heart, passes to the diaphragmatic surface. Along the way in the atrioventricular groove, this circumflex segment of the right VA gives off several branches of variable size to the right atrium and right ventricle (see Fig. 40, A; 46, 50).

Sharp edge artery

The acute margin artery, or right marginal artery, is one of the largest branches of the right VA. It descends from the right VA along the sharp right edge of the heart and often reaches the apex (and sometimes moves to the posterior surface of the heart) or reaches the middle of the right ventricle (see Fig. 46-48, 50). This is the largest collateral branch of the right VA (D. Luzha, 1973; D. Lewin and G. Gardiner, 1988), forming the most powerful (of all branches) anastomoses with the LAD. The artery is involved in feeding the anterior and posterior surfaces of the acute edge of the heart.

On the posterior surface of the right ventricle, the right VA divides into small terminal branches leading to the right atrium and right ventricle. Having given off a large branch - the branch of the acute edge (the right ventricular branch heading to the apex) - and having gone around the tricuspid valve, the right V A then follows along the posterior surface of the heart along the atrioventricular groove to the cross of the heart. Here it forms a U-shaped bend along the inflow septum and, having given off the artery of the atrioventricular node, is directed along the posterior interventricular groove down to the apex (Fig. 51).

Artery of the atrioventricular node

The artery of the atrioventricular node is directed into the thickness of the myocardium through fibrous and fatty tissue under the coronary sinus. According to most authors,

Rice. 51. Course of the right (RVA) and left (LVA) coronary arteries in the atrioventricular groove.

A - heart drug. View from the back and from the base of the heart.

It can be seen that the right coronary artery, arising from the aorta (A), goes around the tricuspid valve (T) and, having given off the LVAD, goes further towards the left atrioventricular groove. It is involved in the blood supply to the posterior wall of the left ventricle. The left coronary artery bends around the mitral valve (M) only in front and does not participate in feeding the posterior wall of the left ventricle.

B - diagram.

A - aorta, LA - pulmonary artery, T and M - tricuspid and mitral valves, RV and LV - right and left ventricles, LVA - left coronary artery, LVV - posterior interventricular branch (from the PVA), VTK - obtuse edge branch.

(J) - artery of the atrioventricular node; (§) - posterolateral branch.

Here and in all subsequent figures, the VA digital designation code shown in Fig. 70.

Rice. 52. Vascularization of the anterior interventricular septum (IVS).

Scheme. View of the IVS from the right ventricle.

The right superior septal artery (1) is most often a branch of the right coronary artery (RCA), but can also arise from the conus artery (CA). The left superior septal artery (2) is usually a branch of the anterior interventricular branch (LAD). Both arteries participate in the vascularization of the atrioventricular node and the His bundle. W. McAlpine (1975) defines other septal branches of the LAD (shown by arrows) as anterior septal branches.

Rice. 53. Vascularization of the atrioventricular (atrioventricular) node (AVN) and His bundle.

3 and P - posterior and right sinuses of Valsalva, a. RV - artery of the atrioventricular node, RV and LV - right and left ventricles, LA - left atrium, T - tricuspid valve, p - penetrating part, c - branching part of the atrioventricular node .

A - aorta, PA - pulmonary artery, PSM - anterior papillary muscle, OB - circumflex branch, DV - diagonal branch, AOC - acute edge artery.

the artery of the atrioventricular node in 88-90% of cases is supplied with blood from the right VA system (see Fig. 40, 42, 43), in approximately 10% of cases - from the left VA system and occasionally from a mixed source (V.V. Kovanov and T.N.Anikina, 1974; K.Anderson etal., 1979; G. Gensini, 1984).

According to T. James (1958), the interventricular septum and the conduction system of the heart are vascularized at two levels. The distal part of the atrioventricular node, the bundle of His and its two legs are localized in different parts of the interventricular septum. The former are supplied with blood from the artery of the atrioventricular node, while the bundle branches and Purkinje fibers are vascularized from the septal branches of the LAD and the septal branches of the LAD. According to W. McAlpine, the area of the atrioventricular node is partially supplied with blood by both the right and left superior septal arteries (Fig. 52, 53).

Posterior interventricular branch

The ZMZHV may be a direct continuation of the right VA, but more often it is its branch. This is one of the largest branches of V A, which along the posterior interventricular groove gives off posterior septal branches, which, firstly, anastomose with the branches of the LAD of the same name, and secondly, as already noted, participate in the vascularization of the terminal sections of the conducting vein. heart systems.

Approximately a quarter of patients with the right type of dominance have significant variations in the origin of the cervical vein. These options include double LVAD, early LVAD (before reaching the cross of the heart), etc.

Posterolateral branch of the left ventricle

According to the materials of G. Gensini and P. Esente (1975), in approximately 20% of cases the right VA forms the posterolateral branch of the left ventricle. This terminal section of the right VA is called the right circumflex artery by V.V. Kovanov and T.N. Anikina (1974). We believe that the right circumflex artery is the entire right VA in the space between the conal artery and the last descending branch of the right VA. The right VA may in some cases extend to the obtuse margin branch, and in these cases the posterolateral left ventricular branch is a branch of the right VA.

With the left type of dominance, the right VA, as a rule, does not reach the cross of the heart. With this variant of dystopia of the VA, the posterior interventricular branches (usually one or two) and the LVV begin with the OB of the left VA. In this case, the artery of the atrioventricular node is often also a branch of the OB of the left VA.

Left coronary artery system

The left coronary artery arises from the left (2nd facial) sinus of the aorta (see Fig. 41-43, 48, 54) immediately below the line of the sinotubular junction. The trunk of the left VA in different hearts varies noticeably in length, but usually it is short and rarely exceeds 1.0 cm. The left VA, as a rule, arises with one trunk, bending around the back of the pulmonary trunk, and at the level of the non-facial sinus of the pulmonary artery it is divided into branches , more often two: LAD and OV.

As noted above, in 40-45% of cases, the left VA, even before dividing into main branches, can give off the artery that supplies the sinus node. This artery may be a branch and OB of the left VA.

Anterior interventricular branch

The LAD follows down along the anterior interventricular septum and reaches the apex of the heart. Occasionally, doubling of the LAD is observed, and very rarely, independent separation of the LAD from the 2nd facial sinus of the aorta is observed. Less often, the LAD does not reach the apex of the heart, but in approximately 80% of cases it reaches the apex and, bending around it, passes to the posterior surface of the heart.

Rice. 54. Corrosive drug.

View of the coronary arteries and aortic orifice (A) on the left. Left lateral projection.

The left coronary artery (LCA) arises from the 2nd facial sinus of the aorta (2) and divides into the anterior interventricular (LAD) and circumflex (OB) branches. In this projection, the LAD occupies the extreme left position along the anterior surface of the heart. The OB almost immediately (this is observed very often) gives rise to a large branch - the obtuse edge branch (BTK). Next, the OB bends around the mitral valve (M), located at an obtuse angle to the plane of the base of the aorta. The LMCA in this heart is a branch of the right coronary artery. The terminal superficial branch of the OB is layered on it.

Its permanent branches are the diagonal (sometimes two or even three), septal branches and the right ventricular branch.

A. On the anterior surface of the heart, the LAD gives rise to a variable artery - right ventricular branch. This artery is a remnant of the fetal circle of Viessen and becomes of great importance in both congenital heart disease and coronary artery disease, especially with high occlusions of the LAD.

B. Septal branches LADs vary greatly in size, number and distribution. More often, a large 1st septal branch (or anterior septal branch) is identified, oriented vertically and breaking up into several secondary branches that frame the anterior interventricular septum (Fig. 55). In some cases, the 1st septal branch is located parallel to the LAD itself. Rare cases of its spontaneous passage have also been described (W. McAlpine, 1975). This artery is also involved in the blood supply to the conduction system of the heart (Fig. 56). Therefore, in the literature there are indications of the need for its independent shunting, especially in cases where its mouth is localized between two areas of LAD stenosis

(B.V. Shabalkin and Yu.V. Belov, 1984; J. Moran et al., 1979).

Septal ischemia resulting from occlusion of the anterior septal artery (1st septal branch of the LAD) leads to the development of ventricular tachycardia.

Rice. 55. The first septal branch (2) of the anterior interventricular branch (1) (according to R. Anderson and A. Becker, 1980).

Heart specimen (left) and angiogram (right).

Rice. 57. The first (anterior) septal branch in dogs (according to J. Twedell et al., 1989) and its role in myocardial infarction.

LVA - left coronary artery, OB - circumflex branch, ASA - anterior septal artery, LAD - anterior interventricular branch.

1-5 - zones of infarction of the anterior interventricular septum on transverse sections of the heart from the base to the apex.

Rice. 56. Diagram of the septal branches of the anterior interventricular branch.

View of the anterior interventricular septum (AIV) from the front, from the side of the outflow tract of the right ventricle (the anterior wall of the right ventricle has been removed).

The first septal branch (1st SV) is most often the first branch of the LAD. It is usually larger than the other septal branches of the LAD. The LAD is more likely than other arteries to be “diving”.

The circumflex branch (CB), immediately after leaving the left coronary artery, is “lost” in a thick layer of fatty tissue. Its intraoperative exposure is also difficult due to the overhang of the left atrial appendage (LAA) (cut off in the figure). The figure shows the left sinus artery (ASA) arising from the left coronary artery. This type of blood supply to the sinus node occurs in 10-12% of cases.

LV - left ventricle, RA - right atrium, T - tricuspid valve, NG - supraventricular crest, PSM - anterior papillary muscle, LA - pulmonary artery, A - aorta, SVC - superior vena cava, PV - pulmonary veins (in the figure - left).

cardia (J. Twedell et al, 1989), arising, as a rule, from the subendocardium and, more often, from the left ventricle (M. DeBakker et al, 1983; L. Harris et al, 1987; J. Twedell et al, 1989). Therefore, adequate protection of this region of the heart during open heart surgery becomes important.

In dogs, this artery supplies the interventricular septum by 75-80% (Fig. 57). It is clear that occlusion of this artery causes myocardial infarction in them.

W. McAlpine (1975) also identifies the so-called “superior septal artery,” although he notes that in humans it is usually small in size or completely absent. F. Rodriguez et al. (1961) also believe that in humans it occurs only in 12-20% of cases. This artery is very important in some animals. For example, in a bovine heart it can supply blood to up to 50% of the septum area. But in humans, its isolation seems to us not entirely justified, especially since in humans in most cases it is represented

V as a branch of the first septal artery.

U in humans, the remaining septal branches of the LAD (“anterior”), as a rule, have

smaller size (see Fig. 47) (D. Lewin and G. Gardiner, 1988). These branches communicate with similar branches of the LVV (“lower”), forming a network of potential collateral vessels. And although the “effectiveness” of such collaterals has not been proven, it is a fact that the interventricular septum is the most vascularized region of the heart.

In humans, the “anterior” septal branches are larger than the “lower” ones (the branches of the cervical vein), but they can also be of equal caliber.

The atria, part of the wall of the left ventricle (LV) and arterial vessels (at the level of the sinuses of Waltz) are removed. The left coronary artery (LCA), arising from the aorta (A), gives off the circumflex branch (OB), which follows posteriorly along the atrioventricular grooves, going around the mitral valve (M).

Rice. 58. Heart preparation.

(P. Fehn et al., 1968). And, on the contrary, in quails the “lower” septal branches are larger than the “upper” ones. In them, most of the septum is supplied with blood by the “lower” septal arteries.

B. Diagonal branch(s)

The LAD, following along the anterolateral surface of the left ventricle, is usually one of those branches that feed the apex (see Fig. 48, 54).

Median artery

In 37% of cases, instead of a bifurcation of the left VA, there is a trifurcation (D. Lewin et al, 1982). In these cases, the “diagonal branch” is called the median artery, and it, like the OB and LAD, arises from the trunk of the left VA. In these hearts, the median artery is the equivalent of a diagonal branch, and it vascularizes the free wall of the left ventricle (D. Lewin and G. Gardiner, 1988).

Enveloping branch

The OB is the next major branch of the left VA and in some cases can branch off from

aortic sinuses independently. It follows along the left atrioventricular groove (see Fig. 43) and, going around the mitral valve (Fig. 54, 58) and the left (blunt) edge of the heart, passes to its diaphragmatic surface.

As already noted, more often (in 90% of cases) it is non-dominant and varies noticeably in size and length, which is determined mainly by the length to the dominant right VA. It is clear that to define such conditions as OB hypoplasia

inappropriate.

Usually the OB gives off the left fragment of the Kugel artery (see Fig. 56), and although more often it does not reach the sinus node, in 10-12% of cases the artery of the sinus node can be formed by this branch.

The OB gives 1-3 large branches of a blunt edge, following downward from the atrioventricular groove (Fig. 59), and very often the OB system is generally represented by a large VTK and an unexpressed OB.

A. Branch of the artery of the obtuse edge (left

		marginal branch) is the largest branch
		view OB (see Fig. 54, 60) and can depart as
	Rice. 59. Heart preparation.	from the beginning of the OB, and at the level of the obtuse edge.
	Rice. 59. Heart preparation.	This is a very important branch involved in pita
		This is a very important branch involved in pita
	Atria and arterial vessels (at the level of the sinus	of the free wall (its anterior and posterior
	Valsalva's owls) are removed.	surface) of the LV along its lateral
	The envelope branch (OB), having given its largest	surface) of the LV along its lateral
	The envelope branch (OB), having given its largest	edges. In a whole number of hearts, OB is generally before
	branch - obtuse edge branch (BTK) - and going around the mit	edges. In a whole number of hearts, OB is generally before
	ral valve, usually gives off one or more	placed by a branch of a blunt edge (Fig. 60).
	posterolateral left ventricular branches and with le	OB, in addition, can give rise to le-
	In this type of blood supply to the heart ends in	OB, in addition, can give rise to le-
	In this type of blood supply to the heart ends in	atrial branch feeding the lateral and
	in the form of the posterior interventricular branch (POIB).	atrial branch feeding the lateral and
	RV and LV - right and left ventricles.	posterior surface of the left atrium.

Rice. 60. Anatomy of the coronary arteries supplying the lateral and posterior walls of the left ventricle (LV).

LC - pulmonary valve, SVC and IVC - superior and inferior vena cava, M - mitral valve, KS - coronary sinus, L and 3 - left and posterior sinuses of the aorta, SVA - right coronary artery, a.RV - arteryatrioventricular-node, RA - right atrium.

B. The terminal branch of the OB is often posterolateral (left ventricular) branch, but the origin of this branch, as well as the MRV and the artery of the atrioventricular node from the OB of the left VA, is determined by the dominance of the right or left VA.

With a balanced type of blood supply to the heart, the ventricular vein is vascularized from the systems of both VAs (both right and left).

Thus, the epicardial trunks of the right VA system are involved in the vascularization of the right atrium, interatrial septum, free wall of the right ventricle, posterior wall of the interventricular septum, papillary muscles of the right ventricle and partially the posteromedial group of papillary muscles of the left ventricle.

The sinus node most often (in 55-60% of cases) is the zone of blood supply to the right VA. Atrioventricular node with predominant pain

In most cases (up to 90% of cases), it is also supplied with blood from the right VA system. The area of blood supply to the left VA includes the left atrium, the anterior, lateral and most of the posterior wall of the left ventricle, the anterior interventricular septum and the anterolateral group of papillary muscles of the left ventricle. Considering the significant variability of VA branching, the study of variant

W. Grossman, 1986). In addition, the anatomy of each of the main epicardial arteries has a number of features, and the role of their branches in the blood supply to the myocardium in each specific case is ambiguous.

This section of the work is devoted to the study of these features. We believe that with the growing interest in coronary artery bypass surgery, knowledge of these features, which are not outlined in domestic guidelines, would be useful.

Our understanding of the surgical anatomy of the VA will be incomplete if we do not briefly dwell on the relationship of the VA with the atrioventricular valves. Further advances in prosthetics or plastic reconstruction of atrioventricular valves are largely due to accurate knowledge of the topographic-anatomical relationships of these valves with adjacent structures of the heart and, in particular, with the vessels of the heart.

According to G.I. Tsukerman et al. (1976), the most dangerous zones are the areas of the external and internal commissures of the mitral valve, in which the circumflex branch of the left VA is as close as possible to its fibrous ring. As shown by the studies of V.I. Shumakov (1959) and L.G. Monastyrsky (1965), the projection of the fibrous ring of the mitral valve is located below the circumflex branch of the left VA on the anterior wall and below the venous sinus - on the posterior, but in hearts with a small size (up to 12 cm in length) on the front wall, this discrepancy in more than half of the cases does not exceed 1-6 mm. The intimate adherence of the mitral valve to these structures creates objective prerequisites for their iatrogenic damage (D. Miller et al., 1978), fraught with the development of irreversible changes in the myocardium and even the death of patients (G.I. Tsukerman et al., 1976; S.S. Sokolov, 1978). Envelope ligation

branches of the left VA is a dangerous complication and occurs in 1.2-3.1% of cases during mitral valve replacement (G.I. Tsukerman et al., 1976). A real possibility of ligating the circumflex branch of the left VA also exists during MV annuloplasty in the case of deep suturing of the fibrous ring (V. A. Prelatov, 1985).

Due to the fact that with sharp calcification of the valve and the spread of calcium to the fibrous ring (and sometimes to the wall of the atrium and ventricle), a sharp thinning of the myocardium occurs, in order to prevent damage to the circumflex branch of the left VA G. I. Tsukerman et al. (1976) advise not to resort to complete decalcification of the valve and fibrous ring, strengthening (to prevent calcification from chipping) these areas with Teflon sutures from the atrium and ventricle. In addition, due to the danger of fistula formation between the coronary sinus and the cavity of the left ventricle, D. Miller et al. (1978) recommend that when reimplanting prostheses, attention should be paid to maintaining the integrity of the posterior wall of the left ventricle.

In this section of the work, we did not dwell on the surgical anatomy of rare variants of the origin, following and branching of the VA. The surgical features of VA in congenital heart disease have not been described. These materials are presented in more detail in the relevant sections.

Surgical anatomy of the atrial coronary arteries

Until recently, the description of the arterial blood supply to the atria has not received due attention. In classical works on anatomy there is only reference to the fact that the atrial arteries arise from the right or left coronary artery (S. S. Mikhailov, 1987; N. Gray, 1948; W. Spatelholz, 1924). Meanwhile, the increasing capabilities of cardiac surgery have made it possible to expand the scope of surgical interventions on the atrial complex. The safety of such interventions is largely determined by the preservation of the coronary arteries (VA), which supply blood to the most important elements of the conduction system of the heart - the arteries of the sinoatrial node (SNA) and the atrioventricular node (AVN). (B. A. Konstantinov et al., 1981; S. Marcelletti, 1981). Due to the small number of reports covering the variant anatomy of these VAs, we present the results of our own studies of the variant anatomy of the SPU and PVA arteries in comparison with literature data.

Despite the fact that W. Spatelholz (1924) developed a regional diagram of the atrial arteries, at present the existence of the anterior, intermediate, posterior right and left atrial arteries (described by this author) has not been confirmed. Of this group, the only more or less permanent atrial coronary artery is the so-called right intermediate atrial artery. It arises from the right coronary artery (RCA) in the area of the sharp edge, goes vertically upward and supplies the myocardium of the corresponding zone of the right atrium. It usually anastomoses with the arteries surrounding the ostium of the superior vena cava (SVC), and therefore its damage is not associated with fatal consequences.

The most permanent atrial coronary arteries are the arteries supplying the sinoatrial and atrioventricular nodes. The first ones go first, and the last ones go last branches of the right or left (or both) VA.

The blood supply to the sinoatrial node is carried out mainly by the SPU artery (Fig. 61), damage to which, despite the abundance of additional sources of blood supply, leads to irreversible disturbances in heart rhythm. According to A. A. Travin et al. (1982), there are two types of origin of the SPU artery. With the right type of blood supply to the heart, the SPU artery begins from the SVA (61.4% of cases), and with the left type, from the left coronary artery (LCA) (38.6% of cases). As the studies of these authors have shown, in 47.5% of cases the artery goes around the SVC mouth on the right, in 37.5% - on the left, and in 15% of cases the SVC mouth is covered in the form of a ring. According to T. James and G. Burch (1958), the SPU artery arises from the SVA in 6-1% of cases, and from the left in 39% of cases. Approximately the same data is given by S. Marcelletti (1981): in

Rice. 61. Options for the origin and distribution of the artery of the sinoatrial node (SNA).

A - origin of the SPU artery (1) from the right coronary artery (RCA); B - origin of the SPU artery (2) from the left coronary artery (LCA). In both cases, the SPU artery is located on the anterior surface of the atrial complex.

C, D - origin of two branches of the SPU artery from the SVA and LVA. In both cases, one artery of the SPU (arising from the SVA) extends along the anterior surface of the atrial complex, the other (being a branch of the SV LVAD) spreads along the posterior surface of the atrial complex.

D, E - artery SPU (1), which is the terminal branch of the SVA, goes around the atrial complex from behind, then passes to its anterosuperior surface (shown by the dotted line) and goes around the mouth of the SVC from behind (E).

SVC and IVC - superior and inferior vena cava, RA and LA - right and left atria, RV and LV - right and left ventricles, A - aorta, LA - pulmonary artery, M - mitral valve, CS - coronary sinus, LAD - anterior interventricular branch, DV - diagonal branch, OB - circumflex branch, PVV - posterior interventricular branch.

In b% of cases, the SPU artery arises from the SVA. Regardless of the source of blood supply, the SPU artery reaches the SVC anteriorly or posteriorly or (less commonly) surrounds its opening

(K. Anderson and S. Ho, 1979).

According to W. McAlpine (1975), the SPU artery in 48% of cases is a branch of the SVA, in 30% - a branch of the LVA, in 22% of cases - the posterior branch of the right or left VA. In 1968, A. Moberg noted that atrial VAs can also arise from extracardiac vessels. W. McAlpine (1975) cites in his atlas one such case, described by N. Nathan et al. (1970). In it, the SPU artery is a branch of the right bronchial artery (Fig. 62).

Having studied more than 500 hearts, we did not find a single such case. But in one heart with a false single VA, independent branching of the SPU artery from the aorta was detected (Fig. 63). In this heart we discovered a second artery that feeds the SPU and is a branch of the equivalent of the PVA. The rarity of our observation lies in the fact that in this heart there was only a single SVA, from which the branches of the right and left VA originated. The only vessel arising from the 2nd facial sinus of the aorta was the left artery of the SPU. However, the presence of the second (right) artery of the SPU, even in this rare observation, confirmed our opinion that the supply of the SPU is carried out, as a rule, by many branches of the right and left VA. Therefore, the allocation of arteries supplying the node is equal to

Rice. 62. Origin of the artery of the sinoatrial node (SNA) from the bronchial artery.

The designations are the same as in Fig. 61.

Rice. 63. The origin of the SPU artery (2) is an independent mouth from the 2nd facial sinus of the aorta (A).

A, B, C - the SPU artery (2) is the equivalent of a branch extending from the LVA. It extends in front of the pulmonary artery (PA) (fragment A), passes under the left atrial appendage (L) (fragment B) and spreads along the posterior surface of the atrial complex.

The ventricular complex is supplied with blood by a false single VA (1), extending from the 1st facial sinus of the aorta.

D - the second artery of the SPU is the equivalent of a branch arising from the SVA. It spreads along the anterior surface of the ventricular complex, bends around the right atrium appendage in front and is seen to have entered the suture (white arrow) in the cannulation area.

The origin of the false single VA from the 1st facial sinus of the aorta is visible.

The blood supply to the heart is carried out by two arteries: the left and right coronary arteries.

Left coronary artery (LKA) departs at the level of the left aortic sinus. Heading towards the left side of the coronary sulcus, behind the pulmonary trunk it divides into two branches: anterior descending artery(anterior interventricular branch) and left circumflex branch. In 30-37% of cases, the third branch arises here - intermediate artery(ramus intermedius), crossing obliquely the wall of the left ventricle.

The branches of the LMCA vascularize the left atrium, the entire anterior and most of the posterior wall of the left ventricle, part of the anterior wall of the right ventricle, the anterior parts of the interventricular septum and the anterior papillary muscle of the left ventricle.

Anterior descending artery (ADA) descends along the anterior interventricular groove to the apex of the heart. On her way she gives anterior septal(S1-S3) branches, which depart from the anterior descending artery at an angle of approximately 90 degrees, pierce the interventricular septum, anastomosing with the branches posterior descending branch ( posterior descending artery). In addition to the septal ones, the LAD gives off one or more branches - diagonal arteries (D1-D3). They descend along the anterolateral surface of the left ventricle, vascularizing the anterior wall and adjacent parts of the lateral wall of the left ventricle.

The LAD supplies the anterior part of the interventricular septum and the right bundle branch (via the septal branches), and the anterior wall of the LV (via the diagonal branches). Often (80%) the apex and partially the lower diaphragmatic wall.

Left circumflex branch ( LOG) follows the left side of the coronary sulcus and at its posterior section passes to the diaphragmatic surface of the heart. In 38% of cases its first branch is sinoatrial node artery. Further, one large or up to three smaller branches depart from the LOG - artery (branches) of the obtuse margin(OM). These important branches supply the free wall of the left ventricle. When moving to the diaphragmatic surface of the LOG gives posterobasal branch of the left ventricle, feeding the anterior and posterior walls of the left ventricle. In the case when there is a right type of blood supply, the LOG gradually becomes thinner, giving off branches to the left ventricle. In the relatively rare left type (10% of cases), it reaches the level of the posterior interventricular groove and forms rear descending branch ( posterior interventricular branch). The LOG also forms important atrial branches, which include left atrial circumflex artery And large anastomosing artery of the auricle.

The LOG supplies most of the lateral wall of the LV; vascularization of the anterior basal part, middle and apical areas of the LV is carried out together with the LAD. Often the LOA supplies the lower part of the lateral wall unless the RCA is dominant. When dominant, LOX vascularizes a significant part of the lower wall.

Right coronary artery (RCA) arises from the right aortic sinus and passes in the right coronary sulcus. In 50% of cases, immediately at the place of origin, it gives off the first branch - conal artery. It follows up and forward in the direction of the PNA. Vascularizes the anterior wall of the right ventricle and may participate in the blood supply to the anterior part of the interventricular septum. The second branch of PCA is up to 59% of cases sinus node artery, extending back at a right angle into the space between the aorta and the wall of the right atrium and reaching the superior vena cava, surrounding its mouth. In 37% of cases, the artery of the sinoatrial node is a branch of the left circumflex artery. And in 3% of cases there is blood supply to the sinoatrial node from two arteries (both from the RCA and from the LOG). It supplies the sinus node, most of the interatrial septum and the anterior wall of the right atrium. In the anterior part of the coronary sulcus, in the region of the acute edge of the heart, it departs from the RCA right ventricular (RV) marginal branch(s), which in most cases reaches the apex of the heart. Then the RCA moves to the diaphragmatic surface of the heart, where it lies deep in the posterior part of the coronary sulcus. Here it gives branches to the posterior wall of the right atrium and right ventricle: intermediate atrial branch And artery atrioventricular node. On the diaphragmatic surface, the RCA reaches the posterior interventricular groove of the heart, in which it descends in the form posterior descending artery. Approximately at the border of the middle and lower thirds, it plunges into the thickness of the myocardium. It supplies the posterior part of the interventricular septum and the posterior walls of both the right and left ventricles. In approximately 20% of cases, the RCA forms posterolateral branches of the left ventricle. This is the terminal section of the right coronary artery - branches supply the posterior phrenic surface of the left ventricle.

The branches of the RCA vascularize: the right atrium, part of the anterior and entire posterior wall of the right ventricle, the inferior phrenic wall of the left ventricle, the interatrial septum, the posterior third of the interventricular septum, partially the posterobasal sections, the papillary muscles of the right ventricle and the posterior papillary muscle of the left ventricle.

TYPES OF BLOOD SUPPLY TO THE HEART

The type of blood supply to the heart refers to the predominant distribution of the right and left coronary arteries on the posterior surface of the heart. The anatomical criterion for assessing the predominant type of distribution of the coronary arteries is the avascular zone on the posterior surface of the heart, formed by the intersection of the coronary and interventricular grooves “cross” (crux). Depending on which of the arteries - the RCA or LOG reaches this zone, the predominant right or left type of blood supply to the heart is distinguished. The artery that reaches this zone always gives off the posterior interventricular branch (posterior descending artery), which runs along the posterior interventricular groove towards the apex of the heart and supplies the posterior part of the interventricular septum. Another anatomical sign is described to determine the predominant type of blood supply. It has been noted that the branch to the atrioventricular node always arises from the predominant artery, i.e. from the artery that is most important in supplying blood to the posterior surface of the heart.

Thus, with predominant right type of blood supply to the heart The RCA supplies the right atrium, right ventricle, posterior interventricular septum, and posterior surface of the left ventricle. The right coronary artery is represented by a large trunk, and the LOG is weakly expressed.

With predominant left type of blood supply to the heart The RCA is narrow and ends in short branches on the diaphragmatic surface of the RV, and the posterior surface of the left ventricle, the posterior part of the interventricular septum, the atrioventricular node, and most of the posterior surface of the LV receive blood from a well-defined large VOC.

In addition, there are also balanced type of blood supply, in which the RCA and LOG make approximately equal contributions to the blood supply to the posterior surface of the heart.

ECG CHANGES DEPENDING ON THE LEVEL OF OCCLUSION OF THE INFARCTION-RELATED CORONARY ARTERY.

I. The most pronounced elevation of the ST segment in the chest, I, aVL.

1. Occlusion of the LPN proximal to the 1st septal (S1) and diagonal (D1) branches. Extensive damage to the anteroseptal area. ST elevation in leads V1-V4 and aVR. Decreased ST in leads II, II, aVF, often in V5-V6. PNPG block with Q wave. The more pronounced the elevation in aVR, the more involved the septum.
2. LPN occlusion proximal to D1 but distal to S1. The anteroseptal or extensive anterior region is affected. ST rise from V2 to V5-6, I, aVL. ST is reduced in leads II, III, aVF.
3. LPN occlusion distal to D1 and S1. Changes in the apical region.

ST raised in V2 V4-5, I, aVL. Slight rise (<2мм) ST в отведениях II, III (II>III), aVF.

4. LPN occlusion proximal to S1 but distal to D1. Changes in the anteroseptal region. ST rise from V1 to V4-5 and aVR. Slight ST elevation in II, III. ST is reduced in V6.
5. Selective occlusion D1. Limited anterolateral area. ST elevation in I, aVL, sometimes V2-V5-6. Decreased ST II, III (III>II), aVF.
6. Selective occlusion S1. Septal region. ST is raised in V1-V2,aVR. Decreased ST in I, II, III (II>III), aVF, V6.

II. The most pronounced ST segment elevation is in the inferior and/or lateral leads.

7. Occlusion of the RCA proximal to the pancreatic marginal branches. Inferior wall and/or inferior septum, damage to the right ventricle. ST elevation in II, III, aVF (III>II). Decreased ST in I, aVL. ST elevation in V4R with positive T. ST on isoline or slight elevation in V1.
8. Occlusion of the RCA distal to the marginal pancreatic branches. The lower wall and/or the lower part of the partition. ST elevation in II, III, aVF (III>II). Decreased ST in I, aVL. Decreased ST in V1-3. With a very small affected area, there is almost no ST in V1-V2.
9. Occlusion of the dominant RCA. Most of the inferolateral zone.

ST elevation in II, III, aVF (III>II). Decrease in ST in V1-3 > rise in ST in II, III, aVF. With proximal RCA occlusion, the ST in V1-V3 is isoelectric or slightly elevated. Decreased ST in I, aVL (aVL >I). ST raised in V5-V6 >2 mm.

10. Occlusion of the LOG proximal to the first OM branch. Lateral and lower walls, especially the lower basal part. ST depression in V1-V3 is more pronounced than ST elevation in the inferior leads. ST elevation in II, III, aVF (II>III). Typically ST lift V5-V6. ST elevation in I, aVL (I >aVL).
11. Occlusion of the first obtuse marginal (OM) artery. Side wall. Often ST elevation in I, aVL, V5-V6 and/or II, III, aVF. Usually small. Often slight ST depression in V1-V3.
12. Occlusion of the dominant LOG. Most of the inferolateral zone.

ST elevation in II, III, aVF (II >/= III) is often greater than ST depression in V1-V3. There may be a decrease in ST in aVL, but not in I. ST elevation in V5-V6 is sometimes very pronounced.