Heart valves: description, structure, function and defects
Heart valves are one of the components of the heartrights. Correct their work provides not only the functioning of the cardiovascular system, but the whole organism as a whole. For this reason, it is very important to know how many heart valves in humans, how they work, how to recognize the signs of valve disease.
The Heart of Man
The human heart is a hollow muscle. It is formed by four chambers: the right and left atrium, the right and left ventricles. Atria with ventricles connect valvular valves. The heart is rhythmically contracted, and blood is supplied portion by part from the atria to the ventricles. Semilunar valves connect the ventricles with blood vessels, through which blood is pushed out of the heart into the aorta and pulmonary artery.
Thus, blood passes through the right chamberswith a high content of carbon dioxide and enters the lungs to enrich with oxygen. And from the lungs, the blood through the left side of the heart is sent back to the bloodstream. Providing a constant pumping of blood through the vessels is the main function that the heart performs.
The valve is necessary in the processpumping of blood. Heart valves provide blood flow in the right direction and in the right amount. Valves are the folds of the inner shell of the heart muscle. These are original "doors" that let the blood flow in one direction and prevent its movement back. Valves open at the moment of rhythmic contraction of the heart muscle. In total, there are four valves in the human heart: two valves and two semilunar ones:
- Bivalve mitral valve.
- Tricuspid tricuspid valve.
- Semi-lunar valve of the pulmonary trunk. Its other name is pulmonary.
- Semilunar aortic valve or aortic valve.
Heart valves open and closeconsistent succession of atrial and ventricular contractions. From their synchronous work depends the blood flow of the vessels, hence, oxygen saturation of all cells of the human body.
Blood, flowing through the vessels in the heart, accumulates in the right atrium. Further advance of it delays tricuspid valve. When it opens, blood enters the right ventricle, from where it is pushed out through the pulmonary valve.
Further, the blood flow enters the lungs to saturateoxygen, and from there is sent to the left atrium through the aortic valve. The heart mitral valve connects the left chambers and holds the blood flow between them, allowing blood to accumulate. After the blood enters the left ventricle and accumulates in the right amount, the blood is pushed into the aorta through the aortic valve. From the aorta, the renewed blood continues its movement along the vessels, enriching the body with oxygen.
Pathologies of the heart valves
The work of the valves is to regulatethe flow of blood passing through the heart of man. If the rhythm of opening and closing the valve apparatus is violated, the heart valves close or open not completely, this can cause many serious diseases. It is noted that mitral and aortic valves are most often affected by pathologies.
Heart defects most often occur in humansover sixty years old. In addition, heart valve diseases can become complications against some infectious diseases. Children are also susceptible to diseases of the valve apparatus. As a rule, these are congenital malformations.
The most common diseases areheart failure and stenosis. In case of insufficiency, the valve closes loosely, and part of the blood returns. Stenosis is called the narrowing of the valve, that is, the valve does not open fully. With this pathology, the heart experiences constant overload, as it takes more effort to push blood.
Heart valve prolapse - The most common diagnosis thatestablishes a doctor with complaints of the patient for malfunctioning of the cardiovascular system. Most often this pathology is affected by the mitral valve of the heart. Prolapse arises from the defect of the connective tissue that forms the valve. As a result of such defects, the valve does not close completely and the blood flows out in the opposite direction.
Separate primary and secondary valve prolapse. Primary prolapse refers to congenital diseases, when connective tissue defects are a genetic predisposition. Secondary prolapse occurs due to trauma to the chest, rheumatism or myocardial infarction.
As a rule, the prolapse of valves does not carry heavyconsequences for human health and is easily treated. But in some cases complications such as arrhythmia (violation of the rhythm of contractions of the heart muscle), insufficiency and others can occur. In such cases, treatment with a medicamental or surgical method is required.
Insufficiency and stenosis of the valve apparatus
The main cause of insufficiency and stenosisis rheumatic endocarditis. Betta-hemolytic streptococcus is the cause of the inflammatory process in rheumatism, reaching the heart, changing its morphological structure. As a result of these changes, the heart valves begin to work differently. The walls of the valves can become shorter, which causes insufficiency, or the valve opening (stenosis) narrows.
Due to rheumatism, mitral valve insufficiency most often occurs in adults. Aortic or mitral heart valve in children is prone to stenosis against rheumatism.
There is such a thing as "relativefailure". Such a pathology occurs if the structure of the valve remains unchanged, but its function is violated, that is, the blood has a reverse outflow. This is due to a violation of the ability of the heart to contract, expand the cavity of the cardiac chamber and so on. Heart failure is also formed as a complication in myocardial infarction, cardiosclerosis, heart muscle tumors.
Lack of qualified treatment of insufficiency and stenosis can lead to inadequate blood flow, dystrophy of internal organs, arterial hypertension.
Symptoms of valve disease
Symptomatic of heart disease directly depends onseverity and extent of the disease. As the pathology develops, the load on the heart muscle increases. While the heart is coping with this load, the disease will be asymptomatic. The first signs of the disease can be:
- failure of the heart rate;
- frequent bronchitis;
- pain in the chest.
Heart failure is often indicatedlack of air and dizziness. The patient experiences weakness and fatigue. Congenital mitral valve prolapse manifests in children with episodic pain in the sternum during stress or overexertion. Acquired prolapse is accompanied by palpitations, dizziness, dyspnea, weakness.
These symptoms may also indicatevegetative-vascular dystonia, aortic aneurysm, arterial hypertension and other cardiac pathologies. In connection with this, it is important to establish an accurate diagnosis, which will reveal that the heart valve gives a malfunction. Treatment of the disease depends entirely on the correct diagnosis.
Diagnosis of diseases
When the first signs of heart disease appearthe valve should be consulted as soon as possible. Reception is conducted by a physician-therapist, the final diagnosis and the appointment of treatment is handled by a narrow specialist - a cardiologist. The therapist listens to the heart to detect noises, and learns the medical history. A further examination is carried out by a cardiologist.
Diagnosis of heart defects is carried out with the help ofinstrumental research methods. An echocardiogram is the main study that identifies valve diseases. It allows you to measure the size of the heart and its departments, to identify violations in the operation of valves. An electrocardiogram records the heart rate, revealing arrhythmia, ischemia, cardiac hypertrophy. X-ray of the heart shows the change in the contour of the heart muscle and its magnitude. In diagnosing the defects of the valve, catheterization is important. The catheter is injected into the vein and promoted through the heart, where it measures pressure.
The possibility of treatment
The medication method includesthe appointment of drugs aimed at removing symptoms and improving the work of the heart. Surgical intervention is aimed at changing the shape of the valve or replacing it. As a rule, patients carry out a form correction operation better than replacement operations. In addition, after the replacement of the heart valve, the patient is prescribed anticoagulants, which will need to be used throughout life.
However, if the valve defect can not be rectified,there is a need to replace it. A mechanical or biological heart valve is used as a prosthesis. The price of the prosthesis largely depends on the country of the manufacturer. Russian prostheses are much cheaper than foreign ones.
Several factors influence the choice of the type of artificial valve. This is the age of the patient, the presence of other diseases of the cardiovascular system, and also which valve is to be replaced.
Mechanical implants last longer, but requireto take coagulants for life. This causes difficulties in the installation of their young women who plan to have children in the future, since taking such drugs is a contraindication during pregnancy. In the case of a tricuspid valve replacement, a biological implant is installed, which is due to the location of the valve in the blood flow system. In other cases, if there are no other contraindications, the installation of a mechanical valve is recommended.