Diagnostics

Human heart muscle, its features and functions. The human heart muscle is characterized

Muscle of life or myocardium

The beating of the heart, its contraction, becomes possible thanks to the middle one, which is called the myocardium or heart muscle. Recall that the human motor consists of three layers: the outer or cardiac sac (pericardium), which lines all the cavities of the heart, the inner (endocardium), and the middle one, which directly provides contraction and shocks - the myocardium. Agree, there is no more important muscle in the body. Therefore, the myocardium can rightly be called the muscle of life.

All departments of the human "motor": atria, right and left ventricles have myocardium in their structure. If we imagine the wall of the heart in a section, then the cardiac muscle occupies a percentage of 75 to 90% of the entire thickness of the wall. Normally, the thickness of the muscle tissue of the right ventricle is from 3.5 to 6.3 mm, the left ventricle is 11-14 mm, and the atria is 1.8-3 mm. The left ventricle is the most "inflated" in relation to other parts of the heart, since it is he who carries out the main work of expelling blood into the vessels.

2 Composition and structure

The heart muscle consists of fibers that have a striated striation. The fibers themselves, upon closer examination, consist of special cells, which are called cardiomyocytes. These are special, unique cells. They contain one nucleus, often located in the center, many mitochondria and other organelles, as well as myofibrils - contractile elements, due to which contraction occurs. These structures resemble filaments, not homogeneous, but composed of thinner actin filaments and thicker myosin filaments.

The alternation of thicker and thinner threads makes it possible to observe striation in a light microscope. A section of myofibril, 2.5 microns in size, containing such a striation is called a sarcomere. It is he who is the elementary contractile unit of the myocardial cell. Sarcomeres are the bricks that make up a huge building - the myocardium. Myocardial cells are a kind of symbiosis of smooth muscle tissue and skeletal tissue.

The resemblance to the musculature of the skeleton ensures the striation of the myocardium and the mechanism of contraction, and from the smooth cardiomyocytes they “took” involuntariness, lack of control over consciousness and the presence in the structure of the cell of one nucleus, which has the ability to change shape and size, thus adapting to contractions. Cardiomyocytes are extremely "friendly" - they seem to hold hands: each cell fits snugly to each other, and between the cell membranes there is a special bridge - an intercalary disk.

Thus, all cardiac structures are closely interconnected with each other and form a single mechanism, a single network. This unity is very important: it allows excitation to spread extremely quickly from one cell to the next, and also to transmit a signal to other cells. Thanks to these structural features, in 0.4 seconds, the transfer of excitation and the response of the heart muscle in the form of its contraction becomes possible.

The heart muscle is not only cells of a contractile nature, it is also cells that have a unique ability to generate excitation, cells that conduct this excitation, blood vessels, elements of connective tissue. The middle shell of the heart has a complex structure and organization, which together play a crucial role in the operation of our motor.

3 Structural features of the muscles of the upper heart chambers

The upper chambers or atria have a smaller thickness of the heart muscle compared to the lower ones. The myocardium of the upper "floors" of a complex "building" - the heart, has 2 layers. The outer layer is common to both atria, its fibers run horizontally and envelop two chambers at once. The inner layer includes longitudinally arranged fibers, they are already separate for the right and left upper chambers. It should be noted that the muscle tissue of the atria and ventricles is not interconnected, the fibers of these structures are not intertwined, which ensures the possibility of their separate contraction.

4 Features of the structure of the muscles of the lower heart chambers

The lower "floors" of the heart have a more developed myocardium, in which there are as many as three layers. The outer and inner layers are common to both chambers, the outer layer goes obliquely to the apex, forming curls deep into the organ, and the inner layer has a longitudinal orientation. Papillary muscles and trabeculae are elements of the inner layer of the ventricular myocardium. The middle layer is located between the two described above and is formed by fibers, separate for the left and right ventricles, their course is circular or circular. To a greater extent, the interventricular septum is formed from the fibers of the middle layer.

5 IVS or ventricular delimiter

Separates the left ventricle from the right and makes the human “motor” four-chambered, no less important than the heart chambers, the formation is the interventricular septum (IVS). This structure allows the blood of the right and left ventricles not to mix, while maintaining optimal blood circulation. For the most part, in its structure, the IVS consists of myocardial fibers, but its upper section - the membranous part - is represented by fibrous tissue.

Anatomists and physiologists distinguish the following sections of the interventricular septum: input, muscular and output. Already at 20 weeks in the fetus on ultrasound, this anatomical formation can be visualized. Normally, there are no holes in the septum, but if there are any, doctors diagnose a congenital defect - an IVS defect. With defects in this structure, a mixture of blood flowing through the right chambers to the lungs and oxygen-rich blood from the left heart sections occurs.

Because of this, normal blood supply to organs and cells does not occur, heart pathology and other complications develop, which can lead to death. Depending on the size of the hole, defects are distinguished large, medium, small, and defects are also classified by location. Small defects can spontaneously close after birth or in childhood, other defects are dangerous for the development of complications - pulmonary hypertension, circulatory failure, arrhythmias. They require prompt intervention.

6 Functions of the heart muscle

In addition to the most important contractile function, the heart muscle also performs the following:

Automation. In the myocardium there are special cells that are able to generate an impulse on their own, independently of any other organs and systems. These cells are crowded and form special nodes of automatism. The most important node is the sinoatrial node, it ensures the work of the underlying nodes and sets the rhythm and pace of heart contractions.
Conductivity. Normally, in the heart muscle, excitation is carried from the overlying sections to the underlying ones through a special fiber. If the conducting system "jumps", then blockades or other rhythm disturbances occur.
Excitability. This function characterizes the ability of cardiac cells to respond to a source of excitation - an irritant. Representing a single network due to the close connection with each other by intercalary discs, the heart cells instantly catch the stimulus and go into an excited state.

It makes no sense to describe the importance of the contractile function of the cardiac “motor”, its importance is clear even to a child: as long as the human heart beats, life goes on. And this process is impossible if the heart muscle does not work smoothly and clearly. Normally, the upper chambers of the heart contract first, followed by the ventricles. During the contraction of the ventricles, blood is ejected into the most important vessels of the body, and it is the ventricular myocardium that provides the force of expulsion. Atrial contraction is also provided by cardiomyocytes included in the wall of these cardiac sections.

7 Diseases of the main muscle of the body

The main muscle of the heart, alas, is prone to disease. When inflammation of the heart muscle occurs, doctors diagnose myocarditis. Inflammation can be caused by a bacterial or viral infection. If we are talking about non-inflammatory disorders of a predominantly metabolic nature, then myocardial dystrophy may develop. Another medical term for heart muscle disease is cardiomyopathy. The causes of this condition may be different, but cardiomyopathies from alcohol abuse are increasingly common.

Shortness of breath, tachycardia, chest pain, weakness - these symptoms indicate that it is difficult for the heart muscle to cope with its functions and it requires examination. The main examination methods are electrocardiogram, echocardiography, radiography, Holter monitoring, dopplerography, EFI, angiography, CT and MRI. You should not write off auscultation, through which the doctor can suggest one or another pathology of the myocardium. Each method is unique and complements each other.

The main thing is to conduct the necessary examination at the initial stage of the disease, when the heart muscle can still be helped and restore its structure and functions without consequences for human health.

This type of muscle is located exclusively in the middle layer of the heart wall - the myocardium. In view of the transverse striation, it can be classified as a striated muscle, and physiologically as a smooth, involuntary muscle. The heart muscle is made up of cells that branch out to form pseudosyncytium. The cells lie end to end, between them are intercalated disks, and between the disks are intercellular junctions that have elongated adhesion sites (girdle desmosomes), as well as small gap junctions that allow contractile impulses to spread from one cell to another.

Single nuclei are located in the center of the cell. Binucleated cells are very rare. The myofibrils of the cardiac muscle are very similar to the myofibrils of the striated muscle. Since they diverge, going around the nucleus, there are enlightenments of the sarcoplasm at each pole. Immediately there are deposits of brown (brown) pigment lipofuscin, the amount of which in the body increases with age.

The fibers of the heart muscle are covered with endomysium, which is a connective tissue well supplied with blood vessels. On a cross section, the cells are irregular in shape and unequal in size, because the heart fibers branch. On the longitudinal section, the filaments of A- and I-bands are revealed, as in the striated muscle. Insert discs have a stepped rather than a linear profile. Cardiac muscle cells are not capable of mitotic division, but thickening of existing fibers (hypertrophy) can occur.

Using electron microscopy, it was shown that the structure of myofibrils of the cardiac muscle is identical to the structure of myofibrils of the striated muscle. The sarcoplasmic reticulum is not as strongly developed and not as highly organized as in striated muscle fibers. Cisterns are present only at the points of contact with T-tubules: the latter are larger than in striated muscle fibers and lie next to the Z-lamellae more often than at the level of the border between A and I-bands. Mitochondria are numerous, especially in the spaces between myofibrils and at the poles of the nuclei, where the Golgi apparatus and glycogen are also concentrated. Inserted discs with a stepped profile consist of transverse sections located at right angles to the long axis of the fiber at the level of Z-plates and longitudinal sections lying parallel to the myofibrils. Both sites contain gap junctions, which are areas of low electrical resistance that provide impulses from one cell to another. The transverse sections of the discs are characterized by desmosomes resembling the girdle desmosomes of the epithelium: for these extensive areas of strong contacts between cells, the term fascia adherens, and not macula adherens, is applicable.

conduction system of the heart.

The nerve impulse to myocardial contraction occurs in the sinoatrial node (pacemaker), which is an accumulation of small cardiomyocytes, poor myofibrils, enclosed in a mass of fibroelastic tissue. The rhythm of contractions of the sino-atrial node is 70 beats per minute. It is located under the epicardium between the right atrial appendage and the confluence of the superior vena cava, and is innervated by accelerating sympathetic and decelerating parasympathetic fibers of the autonomic nervous system. From the sinoatrial node (pacemaker), the nerve impulse passes in the form of depolarization waves through the muscles of both atria to the atrioventricular node, which is located under the endocardium in the wall of the inter-atrial septum. Then thin muscle fibers are bundled together with larger muscle fibers, forming an atrioventricular bundle that exits the atrioventricular node: only in this bundle are the atrial muscle fibers connected to the ventricular muscle fibers, while in other areas they are separated by fibrous rings. tissues (annuli fibrosi). The atrioventricular bundle splits at the beginning of the interventricular septum into right and left legs, branching in the walls of the corresponding ventricles. The muscle fibers in the bundle have a larger diameter (five times) than normal cardiac muscle fibers; these fibers are conductive cardiac myocytes and are called Purkinje fibers. The bundles pass to the apex of the heart, and then each disperse in different directions, with the Purkinje fibers decreasing along the way and branching out in the walls of the corresponding ventricles. Not observed in Purkinje fibers a large number of myofibrils, which are mainly located at the periphery of the cell. As a result, the nucleus is surrounded by a rim of clarified sarcoplasm without any organelles. Purkinje fibers are mostly binucleated and are separated from each other by intercalated discs.

The rhythm of the ventricles is 30 - 40 beats per minute. In the event of damage to the atrioventricular bundle, heart block, the pacemaker-paced atrium maintains the rhythm of contraction of the corresponding ventricle at 70 beats per minute. During this period, on the side of damage, the internal rhythm of the ventricles is half the rhythm of atrial contraction.

It is located in the middle layer between the endocardium and the epicardium. It is she who ensures uninterrupted work on the "distillation" of oxygenated blood to all organs and systems of the body.

Any weakness affects the blood flow, requires compensatory restructuring, well-coordinated functioning of the blood supply system. Insufficient ability to adapt causes a critical decrease in the performance of the heart muscle and its disease.
Endurance of the myocardium is provided by its anatomical structure and endowed with opportunities.

Structural features

It is customary to judge the development of the muscle layer by the size of the wall of the heart, because the epicardium and endocardium are normally very thin membranes. A child is born with the same thickness of the right and left ventricles (about 5 mm). By adolescence, the left ventricle increases by 10 mm, and the right one by only 1 mm.

In an adult healthy person in the relaxation phase, the thickness of the left ventricle ranges from 11 to 15 mm, the right - 5-6 mm.

Features of muscle tissue are:

striated striation formed by myofibrils of cardiomyocyte cells;
the presence of two types of fibers: thin (actin) and thick (myosin), connected by transverse bridges;
the connection of myofibrils into bundles of different lengths and directions, which makes it possible to distinguish three layers (superficial, inner and middle).

The cardiac muscle is different in structure from the skeletal and smooth muscle muscles that provide movement and protection of internal organs.

Morphological features of the structure provide a complex mechanism for contraction of the heart.

How does the heart contract?

Contractility is one of the properties of the myocardium, which consists in creating rhythmic movements of the atria and ventricles, which allow pumping blood into the vessels. The chambers of the heart constantly go through 2 phases:

Systole - caused by the combination of actin and myosin under the influence of ATP energy and the release of potassium ions from cells, while thin fibers slide over thick ones and the bundles decrease in length. The possibility of undulating motions has been proved.
Diastole - there is a relaxation and separation of actin and myosin, the restoration of the expended energy due to the synthesis of enzymes, hormones, vitamins obtained through the "bridges".

It has been established that the force of contractions is provided by calcium entering inside the myocytes.

The entire cycle of heart contraction, including systole, diastole and a general pause after them, with a normal rhythm fits into 0.8 seconds. It begins with atrial systole, the ventricles are filled with blood. Then the atria "rest", passing into the diastole phase, and the ventricles contract (systole).
The calculation of the time of "work" and "rest" of the heart muscle showed that per day the state of contraction accounts for 9 hours 24 minutes, and for relaxation - 14 hours 36 minutes.

The sequence of contractions, ensuring the physiological characteristics and needs of the body during exercise, unrest depends on the connection of the myocardium with the nervous and endocrine systems, the ability to receive and “decipher” signals, and actively adapt to human living conditions.

The spread of excitation from the sinus node can be traced by the intervals and teeth of the ECG

Cardiac mechanisms providing contraction

The properties of the heart muscle have the following goals:

support the contraction of myofibrils;
ensure the correct rhythm for optimal filling of the heart cavities;
maintain the ability to push blood in any extreme conditions for the body.

To do this, the myocardium has the following abilities.

Excitability - the ability of myocytes to respond to any incoming pathogens. Cells protect themselves from suprathreshold stimuli by a state of refractoriness (loss of the ability to excite). In a normal contraction cycle, absolute refractoriness and relative refractoriness are distinguished.

During the period of absolute refractoriness, for 200 to 300 ms, the myocardium does not respond even to superstrong stimuli.
When relative, it is able to respond only to sufficiently strong signals.

With this property, the heart muscle does not allow "distracting" the mechanism of contraction in the systole phase.

Conductivity - the property to receive and transmit impulses to different parts of the heart. It is provided by a special type of myocytes that have processes that are very similar to brain neurons.

Automatism - the ability to create its own action potential inside the myocardium and cause contractions even in a form isolated from the body. This property allows for resuscitation in emergency cases, to maintain the blood supply to the brain. The significance of the located network of cells, their accumulation in the nodes during transplantation of a donor heart is great.

Pacemaker cells (pacemakers) become the main ones if the processes of repolarization and depolarization in the main nodes are weakened. They suppress "alien" excitability and impulses, they try to take on a leadership role. Localized in all parts of the heart. Opportunities are constrained by the sufficient strength of the sinus node.

The value of biochemical processes in the myocardium

The viability of cardiomyocytes is ensured by the supply of nutrients, oxygen and the synthesis of energy in the form of adenosine triphosphoric acid.

All biochemical reactions go as far as possible during systole. Processes are called aerobic, because they are possible only with a sufficient amount of oxygen. In a minute, the left ventricle consumes 2 ml of oxygen for every 100 g of mass.

For energy production, delivered with blood are used:

glucose,
lactic acid,
ketone bodies,
fatty acid,
pyruvic and amino acids,
enzymes,
b vitamins,
hormones.

In the case of an increase in heart rate (physical activity, excitement), the need for oxygen increases by 40–50 times, and the consumption of biochemical components also increases significantly.

What compensatory mechanisms does the cardiac muscle have?

A person does not develop pathology as long as the compensation mechanisms work well. It is regulated by the neuroendocrine system.

The sympathetic nerve delivers signals to the myocardium about the need for enhanced contractions. This is achieved by a more intense metabolism, increased ATP synthesis.

A similar effect occurs with an increased synthesis of catecholamines (adrenaline, norepinephrine). In such cases, the increased work of the myocardium requires an increased supply of oxygen.

If the atherosclerotic narrowing of the coronary vessels does not allow the heart muscle to be supplied in the required volume, then the mediator acetylcholine is released. It protects the myocardium and contributes to the preservation of contractile activity in conditions of oxygen deficiency.

The vagus nerve helps to reduce the frequency of contractions during sleep, during the rest period, to preserve oxygen reserves.

It is important to consider the reflex mechanisms of adaptation.

Tachycardia is caused by congestive stretching of the orifices of the vena cava.

Reflex slowing of the rhythm is possible with aortic stenosis. At the same time, increased pressure in the cavity of the left ventricle irritates the endings of the vagus nerve, contributes to bradycardia and hypotension.

The duration of diastole is increased. Favorable conditions are created for the functioning of the heart. Therefore, aortic stenosis is considered a well-compensated defect. It allows patients to live to a ripe old age.

How to deal with hypertrophy?

Usually prolonged increased load causes hypertrophy. The wall thickness of the left ventricle increases by more than 15 mm. In the mechanism of formation, an important point is the lag in the germination of capillaries deep into the muscle. In a healthy heart, the number of capillaries per mm2 of cardiac muscle tissue is about 4000, and with hypertrophy, the figure drops to 2400.

Therefore, the condition up to a certain point is considered compensatory, but with a significant thickening of the wall leads to pathology. It usually develops in that part of the heart, which must work hard to push blood through a narrowed hole or overcome an obstruction of blood vessels.

A hypertrophied muscle is able to maintain blood flow for a long time in case of heart defects.

The muscle of the right ventricle is less developed, it works against a pressure of 15–25 mm Hg. Art. Therefore, compensation for mitral stenosis, cor pulmonale does not last long. But right ventricular hypertrophy is of great importance in acute myocardial infarction, cardiac aneurysm in the area of the left ventricle, relieves congestion. The significant possibilities of the right departments in training during physical exercises have been proved.

Thickening of the left ventricle compensates for defects in the aortic valves, mitral insufficiency

Can the heart adapt to work in conditions of hypoxia?

An important property of adapting to work without sufficient oxygen supply is the anaerobic (oxygen-free) process of energy synthesis. A very rare occurrence in human organs. Activated only in emergencies. Allows the heart muscle to continue contracting.
The negative consequences are the accumulation of decay products and overwork of muscle fibrils. One is missing for the resynthesis of energy.

However, another mechanism is involved: tissue hypoxia reflexively causes the adrenal glands to produce more aldosterone. This hormone:

increases the amount of circulating blood;
stimulates an increase in the content of erythrocytes and hemoglobin;
enhances venous flow to the right atrium.

This means that it allows the body and myocardium to adapt to a lack of oxygen.

How myocardial pathology occurs, mechanisms of clinical manifestations

Myocardial diseases develop under the influence of various causes, but appear only when the adaptive mechanisms fail.

Prolonged loss of muscle energy, the impossibility of independent synthesis in the absence of components (especially oxygen, vitamins, glucose, amino acids) lead to thinning of the actomyosin layer, break the bonds between myofibrils, replacing them with fibrous tissue.

This disease is called dystrophy. It accompanies:

anemia,
beriberi,
endocrine disorders,
intoxications.

Occurs as a result:

hypertension,
coronary atherosclerosis,
myocarditis.

Patients experience the following symptoms:

weakness,
arrhythmia
shortness of breath on exertion
heartbeat.

At a young age, the most common cause may be thyrotoxicosis, diabetes mellitus. At the same time, there are no obvious symptoms of an enlarged thyroid gland.

Inflammation of the heart muscle is called myocarditis. It accompanies both infectious diseases of children and adults, and those not associated with infection (allergic, idiopathic).

It develops in a focal and diffuse form. The growth of inflammatory elements affects myofibrils, interrupts pathways, changes the activity of nodes and individual cells.

As a result, the patient develops heart failure (more often right ventricular). Clinical manifestations consist of:

pain in the region of the heart;
rhythm interruptions;
shortness of breath;
expansion and pulsation of the cervical veins.

On the ECG fix atrioventricular blockade of varying degrees.

The most well-known disease caused by impaired blood flow to the heart muscle is myocardial ischemia. It flows like this:

angina attacks,
acute heart attack
chronic coronary insufficiency,
sudden death.

The main morphological substrate in this pathology are areas of the heart muscle, depleted in nutrients and oxygen. Depending on the degree of damage, cardiomyocytes change, undergo necrosis.

All forms of ischemia are accompanied by paroxysmal pain. They are figuratively called "the cry of a starving myocardium." The course and outcome of the disease depends on:

speed of assistance;
restoration of blood circulation due to collaterals;
the ability of muscle cells to adapt to hypoxia;
strong scar formation.

Scandalous drug put on the doping list for giving extra energy to the heart muscle

How to help the heart muscle?

The most prepared for critical impacts are people involved in sports. It should be clearly distinguished between cardio training offered by fitness centers and therapeutic exercises. Any cardio program is designed for healthy people. Strengthened training allows you to cause moderate hypertrophy of the left and right ventricles. With properly set work, the person himself controls the sufficiency of the load by the pulse.

Physiotherapy exercises are shown to people suffering from any diseases. If we talk about the heart, then it aims to:

improve tissue regeneration after a heart attack;
strengthen the ligaments of the spine and eliminate the possibility of pinching of the paravertebral vessels;
“boost” the immune system;
restore neuro-endocrine regulation;
ensure the operation of auxiliary vessels.

Exercise therapy is prescribed by doctors, it is better to master the complex under the supervision of specialists in a sanatorium or medical institution

Treatment with drugs is prescribed in accordance with their mechanism of action.

For therapy, there is currently a sufficient arsenal of means:

removing arrhythmias;
improving metabolism in cardiomyocytes;
enhancing nutrition by expanding the coronary vessels;
increasing resistance to hypoxic conditions;
suppressing excess foci of excitability.

You can’t joke with the heart, it’s not recommended to experiment on yourself. Medicines can be prescribed and selected only by a doctor. In order to prevent pathological symptoms for as long as possible, proper prevention is needed. Everyone can help their heart by limiting their intake of alcohol, fatty foods, quitting smoking. Regular exercise can solve many problems.

The heart is rightfully the most important human organ, because it pumps blood and is responsible for the circulation of dissolved oxygen and other nutrients throughout the body. Stopping it for a few minutes can cause irreversible processes, dystrophy and death of organs. For the same reason, diseases and cardiac arrest are one of the most common causes of death.

What tissue forms the heart

The heart is a hollow organ about the size of a human fist. It is almost completely formed by muscle tissue, so many doubt: is the heart a muscle or an organ? The correct answer to this question is an organ formed by muscle tissue.

The heart muscle is called the myocardium, its structure differs significantly from the rest of the muscle tissue: it is formed by cardiomyocyte cells. Cardiac muscle tissue has a striated structure. It contains thin and thick fibers. Microfibrils are clusters of cells that form muscle fibers, collected in bundles of different lengths.

Properties of the heart muscle - ensuring the contraction of the heart and pumping blood.

Where is the heart muscle located? In the middle, between two thin shells:

epicardium;
Endocardium.

The myocardium accounts for the maximum amount of heart mass.

Mechanisms that provide reduction:

There are two phases in the heart cycle:

Relative, in which cells respond to strong stimuli;
Absolute - when for a certain period of time the muscle tissue does not respond even to very strong stimuli.

Compensation mechanisms

The neuroendocrine system protects the heart muscle from overload and helps maintain health. It provides the transmission of "commands" to the myocardium when it is necessary to increase the heart rate.

The reason for this may be:

A certain state of internal organs;
Reaction to environmental conditions;
Irritants, including nervous.

Usually in these situations, adrenaline and norepinephrine are produced in large quantities, in order to "balance" their action, an increase in the amount of oxygen is required. The faster the heart rate, the more oxygenated blood is carried throughout the body.

Features of the structure of the heart

The heart of an adult weighs approximately 250-330 g. In women, the size of this organ is smaller, as is the volume of pumped blood.

It consists of 4 chambers:

two atria;
Two ventricles.

The pulmonary circulation often passes through the right heart, and the large circle passes through the left. Therefore, the walls of the left ventricle are usually larger: so that in one contraction the heart can push out a larger volume of blood.

The direction and volume of the ejected blood is controlled by the valves:

Bicuspid (mitral) - on the left side, between the left ventricle and the atrium;
Three-leaved - on the right side;
Aortic;
Pulmonary.

Pathological processes in the heart muscle

With small malfunctions in the work of the heart, a compensatory mechanism is activated. But conditions are not uncommon when pathology develops, dystrophy of the heart muscle.

This leads to:

oxygen starvation;
Loss of muscle energy and a number of other factors.

Muscle fibers become thinner, and the lack of volume is replaced by fibrous tissue. Dystrophy usually occurs "in conjunction" with beriberi, intoxication, anemia, and disruption of the endocrine system.

The most common causes of this condition are:

Myocarditis (inflammation of the heart muscle);
atherosclerosis of the aorta;
Increased blood pressure.

If it hurts heart: the most common diseases

There are quite a lot of heart diseases, and they are not always accompanied by pain in this particular organ.

Often in this area pain sensations that occur in other organs are given:

Stomach
Lungs;
With chest trauma.

Causes and nature of pain

Pain in the region of the heart is:

sharp penetrating when it hurts even to breathe. They indicate an acute heart attack, heart attack and other dangerous conditions.
Aching occurs as a reaction to stress, with hypertension, chronic diseases of the cardiovascular system.
Spasm, which gives into the hand or shoulder blade.

Often heart pain is associated with:

Emotional experiences.

But often occurs at rest.

All pain in this area can be divided into two main groups:

Anginal or ischemic- associated with insufficient blood supply to the myocardium. Often occur at the peak of emotional experiences, also in some chronic diseases of angina pectoris, hypertension. It is characterized by a sensation of squeezing or burning of varying intensity, often radiating to the hand.
Cardiac disturb the patient almost constantly. They have a weak whining character. But the pain can become sharp with a deep breath or physical exertion.