Cardiology: the structure of the heart, the main pathologies and methods of their treatment of heart disease

Cardiology, like any other medical branch, has a history spanning several thousand years. Since ancient times, the work and structure of the cardiovascular system has interested a person, and many outstanding minds have been engaged in a comprehensive study of this issue. For the first time, more or less accurately the structure of the heart was described by Hippocrates in the 5th century BC, mentioning such parts of it as the ventricles and atria.

A revolution in cardiology was made in the II century BC by the Roman physician Gallen. However, the theory and therapy of diseases proposed by him was based on an erroneous conclusion. He was convinced that blood is formed in the liver, then carried through the vessels throughout the body and absorbed by the body, after which a new "batch" of blood is synthesized. Gallen explained the role of the heart indistinctly, attributing to it participation in the respiratory function on a par with the lungs.

This theory was accepted by doctors as the only correct one until the 17th century, when the English physician William Harvey proved its fallacy. A major breakthrough in cardiology occurred during the Renaissance. Leonardo da Vinci made his contribution to this science.

Thanks to the ability to dissect the bodies of the deceased, the scientist received an accurate understanding of the structure of the heart and transferred this to his illustrations.

At the same time, the Belgian biologist Andreas Vesalius was studying the structure of the cardiovascular system. He presented a clear division of vessels into arteries and veins, but incorrectly described their functions. In addition, he could not articulate exactly how blood circulation occurs in small vessels.

William Harvey plays a huge role in the development of modern cardiology. He conducted a simple experiment: he tied a tight ribbon around his own arm. In just a few minutes, swelling began, and blue veins appeared on the skin. The physician correctly concluded that the dressing impedes blood flow. Further experiments, which he performed on dogs, proved that venous blood flows in one direction, and the heart functions as a pump, pumping it over.

His work also contains information about the muscular structure of this organ and the presence of rhythmically contracting valves. Subsequently, Harvey described two circles of blood circulation - a large one, passing through the brain and the whole body, and a small, pulmonary one. Also, the scientist was able to accurately formulate the role of arterial and venous blood, but he could not figure out the mechanism of its saturation with oxygen.

This question was answered by the Italian physician Marcello Malpighi (1628-1694). Using a microscope, he studied the structure of the frog's lungs and discovered in them a branched capillary network, which then connected to larger vessels, arteries and veins. Alexander Shumlyansky finished his research (1748-1795). He proved that the circulatory system is closed throughout.

The conduction system of the heart began to be studied by the Czech physiologist Jan Purkinje. In 1845, he published data on the presence of special fibers that transmit excitation through the muscle tissue of the organ (by the way, they were later named after him). Purkinje's work was continued by the Swiss anatomist Wilhelm Gies, the German scientist Ludwig Aschoff, the Japanese physician Sunao Tavara and other biologists. Thanks to them, by the beginning of the 19th century, cardiology became an independent branch of medicine.

Today, specialists in this area of ​​medical science are engaged in diagnostics, problems conservative and surgical treatment, prevention of diseases of all departments of the cardiovascular systems. Now cardiology is developing by leaps and bounds. Modern scientists have all sorts of new equipment that makes diagnosis much easier.

If we talk about the sections of cardiology, perinatal and natal are distinguished into separate groups, where deal with the pathologies of children under one year old and the fetus in the last stages of pregnancy, children and adults industry.

In each of them, specialists pay attention to the following aspects:

1. Etiology, that is, the study of the causes of the onset of symptoms of a particular disease.
2. Pathogenesis or mechanism of development of pathology. Analysis and explanation of the ongoing physiological changes allow you to choose the optimal treatment tactics.
3. Diagnostics. This is a very extensive and important part of cardiology. An accurate diagnosis determines the outcome of the disease. Currently, doctors widely use the results of cardiogram, angiography and other techniques. The methods for examining patients will be described in more detail below.
4. Conservative treatment. There are about 10 groups of drugs that are widely used in cardiology. These are adrenergic blockers, anticoagulants, calcium antagonists, diuretics, angioprotectors and a host of drugs that stop signs of hypertensive crisis, stroke, myocardial infarction and other cardiovascular pathologies systems.
5. Surgery. Previously, only open operations were available to doctors, which often ended in complications and even death. Now in cardiology clinics, endoscopic procedures, vascular stenting and even heart transplantation have become widespread. All kinds of arrhythmias, sinus bradycardia, paroxysmal tachycardia, extrasystole are successfully stopped by installing a pacemaker.
6. Physiotherapy. It is a good help for increasing the effectiveness of conservative therapy and improving the prognosis in the postoperative period.
7. Prevention of diseases of the cardiovascular system. This issue is constantly focused on by cardiologists in specialized forums. Many doctors are convinced that usually patients have to search for information on their own, which often leads to self-medication and sad consequences. In addition, doctors in hospitals simply do not have the opportunity to pay due attention to the psychosomatics of a person.

Separately, it is worth mentioning the sections of cardiology relating directly to diseases, these are:

• Atherosclerosis and lipid metabolism disorders.
• Arrhythmias.
• Heart failure.
• Coronary heart disease.
• Acute coronary syndrome (includes unstable angina pectoris).
• Myocardial infarction and its complications (aneurysms, thromboembolism, etc.).
• Arterial hypertension and hypotension.
• Myocardial damage (cardiomyopathy and myocarditis).
• Congenital and acquired heart defects (including mitral valve prolapse).
• Endocarditis and pericarditis.

Vascular diseases are closely related to cardiac pathologies, which are also dealt with by cardiology. For example, vegetative-vascular dystonia often precedes the manifestations of ischemia, arrhythmias, fluctuations in blood pressure. Varicose veins of the lower extremities and their inflammation (thrombophlebitis) often end in thrombosis and trophic ulcers.

Cardiology is closely related to the branch of medicine such as hematology, which deals with the treatment and elucidation of the causes of iron deficiency and other types of anemias, diseases of the lymphatic system (lymphostasis, lymphadenitis).

Human heart: structure, symptoms and causes of its pathologies

In almost all textbooks on cardiology, the human heart is compared to a pump.

Indeed, the contraction of this organ provides a continuous process of blood flow through all vessels, without exception, along the so-called circles of blood circulation, large and small.

Through the systemic circulation, blood is supplied to all cells of the human body, including the lungs.

The small circle of blood circulation passes only through the lungs. Thus, the function of gas exchange is carried out. In simple words, without going into complex physiological terms, venous blood in the lungs "changes" the cells carbon dioxide for oxygen, turning into arterial, which again returns to the organs and tissues. The process is reversed there.

Both circles of blood circulation are connected to each other in the four-chambered human heart. This is a cone-shaped organ located on the left side of the chest, 4 main structures are distinguished in its anatomy: two atria and two ventricles, separated by a system of septa and valves. Outside and inside, all structures of the human heart are lined with muscle tissue, myocardium. Its structure is unique. The fact is that all musculature is divided into two groups: smooth and striated or skeletal. Smooth "works" regardless of human consciousness. It forms the basis of the walls of almost all internal organs and provides peristalsis, expansion and narrowing of blood vessels, contraction of the uterus, bladder, etc.

Skeletal muscles "turn on" only in response to conscious impulses from the brain. Its features are strength and endurance. The myocardium combines the "independence" of smooth and structure of striated muscle tissue. It is this structure that ensures the performance of the main function of the human heart.

How does our main body work? Venous blood from the systemic circulation enters the right atrium through the superior vena cava. Then, through the tricuspid valve, it flows into the right ventricle, and from there it is thrown into the pulmonary artery. This is how the small circle of blood circulation begins.

Through the pulmonary veins, arterial blood enters the left atrium, through the mitral valve into the left ventricle, then into the aorta. The systemic circle of blood circulation begins here. Two coronary vessels depart from the aorta, through which the blood supply to the myocardium itself is carried out.

The sequential contraction of the atria and ventricles is regulated by the conducting system of the human heart. It begins in the upper part of the organ from the sinus node, then the excitation passes into the atrioventricular, from where it spreads along the legs of the His bundle and Purkinje fibers. The total excitation of the myocardium can be calculated from the vectors on the ECG.

The pathology of the human heart can occur even with the slightest malfunction at one of the stages of the organ's work.

The causes of these diseases are:

• congenital anomalies of the structure of the chest, vascular bed and heart defects;
• atherosclerotic coronary artery disease, increased cholesterol and low-density lipoprotein levels;
• hypertonic disease;
• violations of the nervous regulation of the myocardium;
• endocrine system pathology;
• infection (often affects the pericardial sac - the pericardium);
• rheumatoid diseases;
• malignant neoplasms.

The predisposing factors for the development of various human heart diseases are smoking, frequent stress, inaccuracies in the diet, overweight, and lack of physical activity.

The following symptoms are common manifestations for all pathologies of this organ:

• pain of varying intensity in the chest area, discomfort may also appear in the left shoulder blade or arm;
• shortness of breath against the background of the usual physical activity, in severe cases - attacks of suffocation;
• increased fatigue;
• weakness;
• increased heart rate or irregularities in the rhythm of the heart;
• swelling of the legs;
• headaches and dizziness are signs of blood pressure problems.

Heart disease: diagnosis and general characteristics

Diagnosis of any pathology, including heart disease, begins with an examination of the patient.

In addition to asking a person about the symptoms that bother him, a lot of information is given to the doctor by the appearance:

• Body type. For example, people of the asthenic type are prone to hypotension, hypersthenic - hypercholesterolemia, high blood pressure.
• Leather. The pallor of the skin usually indicates the pathology of the peripheral circulation, if it is combined with the same shade of the mucous membranes, the likelihood of anemia is high. Cyanosis can be due to heart failure.
• Nails. The specific shape of the nails (in the form of convex watch glasses) and thickening of the phalanges of the fingers, reminiscent of drumsticks, speaks in favor of heart disease.
• The presence or absence of edema and their localization. Heart failure is evidenced by extensive swelling spread throughout the body.
• Joints. Stiffness of movement, swelling is a symptom of rheumatic diseases.

The position of the heart, its size is determined by palpation and percussion. You can listen to the rhythm of myocardial contraction by auscultation. However, a more accurate picture is given by instrumental examinations of the patient. First of all, it is an electrocardiogram or an abbreviated ECG. It is simple to execute, painless, non-invasive, but it gives a lot of information.

After decoding the results, they diagnose arrhythmia, heart attack, conduction disorders. The advantage of the ECG is its availability and the possibility of performing it even in an ambulance. Often this will allow the correct selection of emergency measures and prevent the death of the patient.

A more complete picture is given by echocardiography (EchoCG) or ultrasound of the heart, especially in combination with a Doppler study of blood supply. This allows you to assess the condition of the coronary vessels, valve apparatus, septa. Ultrasound can also determine congenital pathologies.

Exercise tests are other complementary ways to diagnose heart disease. In this case, an ECG is taken during exercise on an exercise bike or a treadmill. Ordinary walking for 6 minutes is sometimes allowed. It all depends on the patient's condition. When conducting tests, attention is paid to changes in the work of the heart, under the influence of a strictly dosed load.

For the diagnosis of chronic coronary heart disease, scintigraphy is indicative. At the same time, a labeled radioisotope preparation is injected into the human body and its movement along the vascular network is monitored using tomography. Also, CT, MRI and conventional X-rays are used to obtain an accurate picture of the internal structure of an organ. To assess hemodynamics and vascular condition, an angiographic examination is performed.

Frequent heart diseases are various arrhythmias, that is, a violation of the physiological rhythm of myocardial contractions, among them are:

• extrasystole, premature contractions out of the usual pattern;
• tachycardia, increased heart rate, is ventricular and supraventricular;
• bradycardia, a slowdown in the frequency of heart beats, this is considered the norm for professional athletes;
• sick sinus syndrome (sinus blockade);
• violations of atrioventricular and ventricular conduction (blockade, premature excitation).

According to the clinical course, arrhythmias can be acute and chronic, transient and constant. The main symptoms of this heart disease are dizziness, throbbing, shortness of breath, and loss of consciousness. To prevent attacks of pathology, the patient has to almost constantly take pills from the group of adrenergic receptor blockers or install an artificial pacemaker.

Ischemic heart disease develops against the background of impaired coronary blood flow and the associated insufficient supply of oxygen to the myocardium. The main cause of this pathology is atherosclerosis. Such a violation is dangerous for its complications. This is myocardial infarction, possible subsequent cardiosclerosis and heart failure.

Usually IHD proceeds against the background of hypertension, manifests itself in the form of attacks of angina pectoris (acute compressive pain in the chest), which are stopped by Nitroglycerin tablets.

Myocardial infarction is a formidable complication of chronic ischemia. The mortality of patients in the first 1-2 hours after is about 30%, but even with hospitalization the probability of death is about 10%. Emergency measures include chest compressions and urgent delivery of the patient to intensive care. There, the patient is injected with drugs to restore blood flow in the affected myocardium, relieve pain, prevent the consequences of acute cardiac muscle hypoxia.

But even with adequate medical care, the risk of recurrence of the pathology remains, especially in old age. Therefore, drugs are shown to normalize blood pressure (especially with concomitant hypertensive disease), diet (food should contain a minimum of fast carbohydrates, animal fats and a maximum of vitamins), folk help well funds. If the patient's condition allows, physical activity is necessary, for this, special exercises from the exercise therapy complex are recommended. Disability often follows myocardial infarction.

What our portal will tell you about: cardiology, treatment and prevention of cardiovascular diseases

As indicated on the portals for cardiology and cardiac surgery, the main means used for the treatment of pathologies of the heart and blood vessels are:

• Alpha blockers (Prazosin, Doxazosin, Terazosin) are widely used to treat severe forms of arterial hypertension occurring with hypertensive crises.
• Calcium channel blockers (Diltiazem, Falipamil, Amlodipine). It is used to treat hypertension, relieve angina attacks, eliminate symptoms of coronary heart disease.
• Antiplatelet and anticoagulants (Heparin, Clopidogrel, Tirofiban, Cardiomagnet). It is prescribed for the prevention and treatment of strokes, thrombotic complications of atherosclerosis.
• Antiarrhythmic drugs (Propranolol, Atenolol, Amiodarone, Nibentan). Prescribed to normalize the heart rate with sinus tachycardia, bradyarrhythmias, extrasystoles.
• Angiotensin receptor blockers (Losartan, Valsartan) are indicated for hypertension, heart failure, coronary artery disease.

The measures for the prevention of diseases of the cardiovascular system include, first of all, a change in lifestyle, nutritional principles, and an increase in physical activity. In addition, the treatment of such pathologies should be combined with immunology, gastroenterology, and metabolic correction. With the development of Russian educational sites, the cardiology portal is becoming more widespread not only among specialists, but also among patients.