Aortic heart valve maximum speed. Aortic (valvular) stenosis (I35.0)

front sash mitral valve without signs of pathology is registered in the second standard position of the sensor in the form of the letter M.
For a better understanding and subsequent interpretation of the parameters, reflecting the mechanism of the mitral valve, we consider it appropriate to give a descriptive characteristic of the movement according to the scheme.

General excursion of the mitral valve is determined in systole by the vertical displacement of the valves in the SD interval, the diastolic divergence is determined horizontally in the interval of the SD segment. The speed of early diastolic opening and closing is calculated graphically according to the method described above by plotting tangents to the corresponding sections of the mitral valve motion curve.

semilunar valves. The aortic valves and the aorta itself are located in the IV standard position of the transducer. In diastole, the valves are recorded on the echocardiogram in the form of a "snake" in the center of the aortic lumen. The divergence of the aortic valves in systole resembles a "diamond-shaped figure."

systolic divergence of the aortic valves equal to the distance between their final sections facing the lumen of the aorta. The lumen of the aorta in systole and diastole is determined by the outlines of its inner surface in the corresponding phases of the cardiac cycle relative to the ECG.

Left atrium, like the aorta, is registered in the IV standard position of the sensor. On the echocardiogram, almost only the posterior wall of the left atrium is recorded. Its anterior wall in echocardiography is considered to coincide with the posterior surface of the aorta. According to the indicated signs, the size of the cavity of the left atrium is determined.

Norm EchoCG (echocardioscopy)

Average echocardiographic parameters are normal(according to the literature):
Left ventricle.
The thickness of the posterior wall of the left ventricle is 1 cm in diastole and 1.3 cm in systole.
The final diastolic size of the cavity of the left ventricle is 5 cm.
The final systolic size of the cavity of the left ventricle is 3.71 cm.
The rate of contraction of the posterior wall of the left ventricle is 4.7 cm/s.
The relaxation rate of the posterior wall of the left ventricle is 10 cm/s.

mitral valve.
The total excursion of the mitral valve is 25 mm.
Diastolic divergence of the mitral valves (at the level of point E) - 26.9 mm.
Transitional leaf opening speed (EG) -276.19 mm/s.
The speed of early diastolic closure of the anterior wall was 141.52 mm/s.

The duration of the valve opening is 0.47±0.01 s.
The amplitude of the front leaf opening is 18.42±0.3& mm.
The lumen of the base of the aorta is 2.52±0.05 cm.
The size of the cavity of the left atrium is 2.7 cm.
End diastolic volume - 108 cm3.

The final systolic volume is 58 cm3.
Stroke volume - 60 cm3.
Faction of exile - 61%.
The speed of circular contraction is 1.1 s.
The mass of the myocardium of the left ventricle is 100-130 g.

Incomplete closure of the aortic valve during diastole, resulting in backflow of blood from the aorta into the left ventricle. Aortic insufficiency is accompanied by dizziness, fainting, chest pain, shortness of breath, frequent and irregular heartbeat. X-rays are used to diagnose aortic insufficiency. chest, aortography, EchoCG, ECG, MRI and CT of the heart, cardiac catheterization, etc. Chronic aortic insufficiency is treated conservatively (diuretics, ACE inhibitors, calcium channel blockers, etc.); in severe symptomatic cases, aortic valve repair or replacement is indicated.

General information

Aortic insufficiency (aortic valve insufficiency) is a valvular defect in which during diastole the semilunar leaflets of the aortic valve do not completely close, resulting in diastolic regurgitation of blood from the aorta back into the left ventricle. Among all heart defects, isolated aortic insufficiency is about 4% of cases in cardiology; in 10% of cases, aortic valve insufficiency is combined with other valvular lesions. The vast majority of patients (55-60%) have a combination of aortic valve insufficiency and aortic stenosis. Aortic insufficiency is 3-5 times more common in males.

Causes of aortic insufficiency

Aortic insufficiency is a polyetiological defect, the origin of which may be due to a number of congenital or acquired factors.

Congenital aortic insufficiency develops when there is a one-, two-, or four-leaf aortic valve instead of a tricuspid one. Causes of an aortic valve defect can be hereditary diseases connective tissue: congenital pathology of the aortic wall - aortoannular ectasia, Marfan's syndrome, Ehlers-Danlos syndrome, cystic fibrosis, congenital osteoporosis, Erdheim's disease, etc. In this case, incomplete closure or prolapse of the aortic valve usually occurs.

The main causes of acquired organic aortic insufficiency are rheumatism (up to 80% of all cases), septic endocarditis, atherosclerosis, syphilis, rheumatoid arthritis, systemic lupus erythematosus, Takayasu's disease, traumatic valve damage, etc. Rheumatic damage leads to thickening, deformation and wrinkling of the valve leaflets aorta, resulting in their complete closure during diastole. Rheumatic etiology usually underlies the combination of aortic insufficiency with mitral valve disease. Infective endocarditis is accompanied by deformity, erosion, or perforation of the leaflets, causing a defect in the aortic valve.

The occurrence of relative aortic insufficiency is possible due to the expansion of the fibrous ring of the valve or the lumen of the aorta with arterial hypertension, aneurysm of the sinus of Valsalva, exfoliating aortic aneurysm, ankylosing rheumatoid spondylitis (Bekhterev's disease), and other pathologies. In these conditions, separation (divergence) of the aortic valve leaflets during diastole can also be observed.

Hemodynamic disorders in aortic insufficiency

Hemodynamic disorders in aortic insufficiency are determined by the volume of diastolic blood regurgitation through the valve defect from the aorta back to the left ventricle (LV). In this case, the volume of blood returning to the LV can reach more than half of the value of cardiac output.

Thus, in aortic insufficiency, the left ventricle during diastole is filled both as a result of blood flow from the left atrium and as a result of aortic reflux, which is accompanied by an increase in diastolic volume and pressure in the LV cavity. The volume of regurgitation can reach up to 75% of the stroke volume, and the end diastolic volume of the left ventricle can increase to 440 ml (at a rate of 60 to 130 ml).

The expansion of the cavity of the left ventricle contributes to the stretching of the muscle fibers. To expel the increased volume of blood, the force of contraction of the ventricles increases, which, in a satisfactory state of the myocardium, leads to an increase in systolic ejection and compensation for altered intracardiac hemodynamics. but long work of the left ventricle in the hyperfunction mode is invariably accompanied by hypertrophy and then dystrophy of cardiomyocytes: a short period of tonogenic dilatation of the left ventricle with an increase in blood outflow is replaced by a period of myogenic dilatation with an increase in blood inflow. The end result is mitralization of the defect - relative insufficiency of the mitral valve, due to LV dilatation, dysfunction of the papillary muscles and expansion of the fibrous ring of the mitral valve.

In conditions of compensation of aortic insufficiency, the function of the left atrium remains unimpaired. With the development of decompensation, there is an increase in diastolic pressure in the left atrium, which leads to its hyperfunction, and then to hypertrophy and dilation. Stagnation of blood in the system of vessels of the pulmonary circulation is accompanied by an increase in pressure in the pulmonary artery, followed by hyperfunction and hypertrophy of the myocardium of the right ventricle. This explains the development of right ventricular failure in aortic disease.

Classification of aortic insufficiency

To assess the severity of hemodynamic disorders and the compensatory capabilities of the body, a clinical classification is used that distinguishes 5 stages of aortic insufficiency:

  • I - stage of full compensation. Initial (auscultatory) signs of aortic insufficiency in the absence of subjective complaints.
  • II - stage of latent heart failure. A moderate decrease in exercise tolerance is characteristic. ECG revealed signs of hypertrophy and volume overload of the left ventricle.
  • III - stage of subcompensation of aortic insufficiency. Typical anginal pain, forced restriction of physical activity. On the ECG and radiographs - left ventricular hypertrophy, signs of secondary coronary insufficiency.
  • IV - stage of decompensation of aortic insufficiency. Severe shortness of breath and attacks of cardiac asthma occur at the slightest exertion, an enlarged liver is determined.
  • V - terminal stage of aortic insufficiency. It is characterized by progressive total heart failure, deep dystrophic processes in all vital organs.

Symptoms of aortic insufficiency

Patients with aortic insufficiency in the stage of compensation do not report subjective symptoms. The latent course of the defect can be long - sometimes for several years. The exception is acutely developed aortic insufficiency due to exfoliating aortic aneurysm, infective endocarditis and other causes.

Symptoms of aortic insufficiency usually manifest with sensations of pulsation in the vessels of the head and neck, increased cardiac tremors, which is associated with high pulse pressure and increased cardiac output. Sinus tachycardia, characteristic of aortic insufficiency, is subjectively perceived by patients as a rapid heartbeat.

With a pronounced valve defect and a large amount of regurgitation, brain symptoms are noted: dizziness, headaches, tinnitus, visual disturbances, short-term fainting (especially with a quick change horizontal position bodies to vertical).

In the future, angina pectoris, arrhythmia (extrasystole), shortness of breath, increased sweating. On the early stages aortic insufficiency, these sensations are disturbed mainly during exercise, and later occur at rest. Attachment of right ventricular failure manifests itself as swelling in the legs, heaviness and pain in the right hypochondrium.

Acute aortic insufficiency proceeds as pulmonary edema, combined with arterial hypotension. It is associated with sudden left ventricular volume overload, increased LV end-diastolic pressure, and decreased stroke output. In the absence of special cardiac surgical care, mortality in this condition is extremely high.

Diagnosis of aortic insufficiency

Physical findings in aortic insufficiency are characterized by a number of typical features. On external examination, the pallor of the skin draws attention, in the later stages - acrocyanosis. Sometimes external signs of increased pulsation of the arteries are revealed - “carotid dance” (pulsation visible to the eye on carotid arteries), Musset's symptom (rhythmic nodding of the head to the beat of the pulse), Landolfi's symptom (pulse of the pupils), "Quincke's capillary pulse" (pulsation of the vessels of the nail bed), Muller's symptom (pulsation of the uvula and soft palate).

Typically visual definition of the apex beat and its displacement in the VI-VII intercostal space; pulsation of the aorta is palpated behind the xiphoid process. Auscultatory signs of aortic insufficiency are characterized by diastolic murmur on the aorta, weakening of I and II heart sounds, "accompanying" functional systolic murmur on the aorta, vascular phenomena (Traube's double tone, Durozier's double murmur).

Instrumental diagnosis of aortic insufficiency is based on the results of ECG, phonocardiography, x-ray studies, echocardiography (TEE), cardiac catheterization, MRI, MSCT. Electrocardiography reveals signs of left ventricular hypertrophy, with mitralization of the defect - data for left atrial hypertrophy. With the help of phonocardiography, altered and pathological heart murmurs are determined. Echocardiography reveals a number of characteristic symptoms aortic insufficiency - an increase in the size of the left ventricle, anatomical defect and functional failure of the aortic valve.

Signs of inoperability are an increase in LV diastolic volume up to 300 ml; ejection fraction 50%, end diastolic pressure about 40 mm Hg. Art.

Forecast and prevention of aortic insufficiency

The prognosis of aortic insufficiency is largely determined by the etiology of the defect and the amount of regurgitation. With severe aortic insufficiency without decompensation, the average life expectancy of patients from the moment of diagnosis is 5-10 years. In the decompensated stage with symptoms of coronary and heart failure, drug therapy is ineffective, and patients die within 2 years. Timely cardiac surgery significantly improves the prognosis of aortic insufficiency.

Prevention of the development of aortic insufficiency consists in the prevention of rheumatic diseases, syphilis, atherosclerosis, their timely detection and full treatment; clinical examination of patients at risk for the development of aortic disease.

Aortic valve examination has been a strength of echocardiography since its introduction into clinical practice in the early 1970s. M-modal echocardiography was initially shown to be reliable in excluding aortic stenosis and highly sensitive in diagnosing aortic insufficiency. With the advent of two-dimensional, and then various Doppler modes, it turned out that echocardiography diagnoses aortic valve pathology so well that it surpasses cardiac catheterization and angiography in its diagnostic value.

Normal aortic valve and aortic root

Examination of the aortic valve begins with its visualization from the parasternal approach in the position of the long axis of the left ventricle. Then, under 2D imaging guidance, usually along the parasternal short axis at the level of the base of the heart, the M-modal beam is directed to the aortic valve leaflets and the aortic root (Fig. 2.2 ). On fig. 2.6 the aortic valve is shown from the position of the parasternal short axis and its M-modal image. The right coronary and non-coronary leaflets of the aortic valve fall into the slice of the M-modal image. The line of their closure in diastole is normally located in the middle between the anterior and posterior walls of the aorta. In systole, the valves open and, diverging anteriorly and posteriorly, form a "box". In this position, the valves remain until the end of systole. Normally, mild systolic trembling of the aortic valve leaflets can be recorded on M-modal examination.

If the normal thin leaflets of the aortic valve do not open fully, this usually means a sharp decrease in stroke volume. With normal stroke volume and dilatation of the aortic root, the valve leaflets, opening, may be somewhat separated from the walls of the aorta. With low stroke volume, the M-modal movement of the aortic valve leaflets sometimes has the shape of a triangle: immediately after full opening, the leaflets begin to close. If the leaflets slam shut after their maximum opening, fixed subvalvular stenosis should be suspected. Mid-systolic closure of the aortic valve leaflets (partial closure in the middle of systole, then again maximum opening) is a sign of dynamic subvalvular stenosis, i.e., hypertrophic cardiomyopathy with obstruction of the outflow tract of the left ventricle. In diastole, the closed leaflets are parallel to the walls of the aorta. Diastolic trembling of the aortic valve leaflets indicates a serious pathology and is observed when the leaflets are ruptured or detached. The eccentric location of the line of closure of the aortic valve cusps makes one suspect a congenital pathology - a bicuspid aortic valve.

Movement of the aortic root can provide valuable information about the global systolic and diastolic function of the left ventricle. Normally, the aortic root is displaced anteriorly in systole by more than 7 mm, and almost immediately returns to its place at the end of it. The movements of the aortic root reflect the processes of filling and emptying the left atrium; during atrial systole, they are normally minimal. With a decrease in the amplitude of movement of the aortic root, one should think about a low stroke volume. Note that the amplitude of motion of the aortic root is not directly dependent on the ejection fraction. For example, with hypovolemia and normal contractility of the left ventricle, the amplitude of movement of the aortic root decreases. Normal or even excessive mobility of the aortic root with a reduced opening of the aortic valve cusps indicates a disproportion between the blood flow in the left atrium and in the aorta and is observed in severe mitral insufficiency.

In a two-dimensional study parasternally along the short axis, the aortic valve looks like a structure consisting of three symmetrically located, equally thin leaflets, which open completely in systole, and close in diastole and form a figure similar to an inverted emblem of a Mercedes-Benz car. The junction of all three valves may look slightly thickened. The aortic root has a larger diameter than the rest of the ascending aorta and is formed from the three sinuses of Valsalva, which are named similarly to the valve leaflets: left coronary, right coronary, non-coronary. Normally, the diameter of the aortic root does not exceed 3.5 cm. A Doppler study of blood flow through the aortic valve gives a spectrum of a triangular shape; the maximum speed of aortic blood flow is from 1.0 to 1.5 m/s. The aortic valve has a smaller diameter than the outflow tract of the left ventricle and the ascending aorta, so the velocity of blood flow is highest at the level of the valve.

Aortic insufficiency is a pathology in which the leaflets of the aortic valve do not close completely, as a result of which the reverse flow of blood into the left ventricle of the heart from the aorta is disrupted.

This disease causes many unpleasant symptoms - chest pain, dizziness, shortness of breath, malfunctions heart rate and other.

The aortic valve is a valve in the aorta, which consists of 3 cusps. Designed to separate the aorta and the left ventricle. In the normal state, when blood flows from this ventricle into the aortic cavity, the valve closes tightly, pressure is created due to which the flow of blood through thin arteries to all organs of the body is ensured, without the possibility of a reverse outpouring.

If the structure of this valve has been damaged, it only partially closes, which leads to the backflow of blood into the left ventricle. Wherein organs stop receiving the necessary amount of blood for normal functioning, and the heart has to contract more intensively to compensate for the lack of blood.

As a result of these processes, aortic insufficiency is formed.

According to statistics, this aortic valve insufficiency occurs in about 15% of people having any heart defects and often accompanies diseases such as the mitral valve. As an independent disease, this pathology occurs in 5% of patients with heart defects. Most often affects males, as a result of exposure to internal or external factors.

Useful video about aortic valve insufficiency:

Causes and risk factors

Aortic insufficiency is formed due to the fact that the aortic valve has been damaged. The reasons that lead to its damage may be the following:

Other causes of the disease, which are much less common, can be: diseases of the connective tissue, rheumatoid arthritis, ankylosing spondylitis, diseases immune system, long-term radiation therapy for the formation of tumors in the chest area.

Types and forms of the disease

Aortic insufficiency is divided into several types and forms. Depending on the period of formation of the pathology, the disease is:

  • congenital- occurs due to poor genetics or the adverse effects of harmful factors on a pregnant woman;
  • acquired- appears as a result of various diseases, tumors or injuries.

The acquired form, in turn, is divided into functional and organic.

  • functional- formed when the aorta or left ventricle expands;
  • organic- occurs due to damage to the tissue of the valve.

1, 2, 3, 4 and 5 degrees

Depending on the clinical picture diseases, aortic insufficiency can be of several stages:

  1. First stage. It is characterized by the absence of symptoms, a slight enlargement of the heart walls on the left side, with a moderate increase in the size of the cavity of the left ventricle.
  2. Second stage. The period of latent decompensation, when there are no pronounced symptoms yet, but the walls and cavity of the left ventricle are already quite enlarged in size.
  3. Third stage. The formation of coronary insufficiency, when there is already a partial reflux of blood from the aorta back into the ventricle. It is characterized by frequent painful sensations in the region of the heart.
  4. Fourth stage. The left ventricle contracts weakly, which leads to congestion in the blood vessels. Symptoms such as shortness of breath, lack of air, swelling of the lungs, heart failure are observed.
  5. Fifth stage. It is considered the dying stage, when it is almost impossible to save the patient's life. The heart contracts very weakly, resulting in internal organs blood stasis occurs.

Danger and complications

If the treatment was started late, or the disease proceeds in acute form,pathology can lead to the development of the following complications:

  • - a disease in which an inflammatory process forms in the valves of the heart as a result of exposure to damaged structures of the valves pathogenic microorganisms;
  • lungs;
  • heart rhythm failures - ventricular or atrial extrasystole, atrial fibrillation; ventricular fibrillation;
  • thromboembolism - the formation of blood clots in the brain and other organs, which is fraught with the occurrence of strokes and heart attacks.

When treating aortic insufficiency surgically, there is a risk of developing complications such as implant destruction, endocarditis. Operated patients often have to take lifelong medication to prevent complications.

Symptoms

Symptoms of the disease depend on its stage. IN initial stages the patient may not experience any discomfort, since only the left ventricle is exposed to the load - a fairly powerful part of the heart, which is able to withstand failures in the circulatory system for a very long time.

With the development of pathology, the following symptoms begin to appear:

  • Pulsating sensations in the head, neck, increased heartbeat especially when lying down. These signs arise due to the fact that a larger volume of blood enters the aorta than usual - the blood that returned to the aorta through a loosely closed valve is added to the normal amount.
  • Pain in the region of the heart. They can be compressive or squeezing, appear due to impaired blood flow through the arteries.
  • Cardiopalmus. It is formed as a result of a lack of blood in the organs, as a result of which the heart is forced to work at an accelerated rhythm in order to compensate for the required volume of blood.
  • Dizziness, fainting, severe headaches, vision problems, buzzing in the ears. Characteristic for stages 3 and 4, when blood circulation is disturbed in the brain.
  • Weakness in the body, fatigue, shortness of breath, heart rhythm disturbances, increased sweating e. At the beginning of the disease, these symptoms occur only when physical activity, in the future they begin to disturb the patient and in a calm state. The appearance of these signs is associated with a violation of blood flow to the organs.

The acute form of the disease can lead to overload of the left ventricle and the formation of pulmonary edema, in conjunction with a sharp decrease in blood pressure. If surgical care is not provided during this period, the patient may die.

When to see a doctor and to whom

This pathology needs timely medical care. If you find the first signs - increased fatigue, throbbing in the neck or head, pressing pain in the sternum and shortness of breath - you should consult a doctor as soon as possible. treatment this disease are engaged therapist, cardiologist.

Diagnostics

To make a diagnosis, the doctor examines the patient's complaints, lifestyle, anamnesis, then the following examinations are carried out:

  • Physical examination. Allows you to identify such signs of aortic insufficiency as: pulsation of the arteries, dilated pupils, expansion of the heart to the left side, an increase in the aorta in its initial section, low blood pressure.
  • Urine and blood analysis. With its help, you can determine the presence of concomitant disorders and inflammatory processes in the body.
  • Biochemical blood test. Shows the level of cholesterol, protein, sugar, uric acid. Necessary in order to identify organ damage.
  • ECG to determine heart rate and heart size. Learn all about .
  • echocardiography. Allows you to determine the diameter of the aorta and pathology in the structure of the aortic valve.
  • Radiography. Shows the location, shape and size of the heart.
  • Phonocardiogram for the study of heart murmurs.
  • CT, MRI, KCG- to study blood flow.

Treatment Methods

In the initial stages, when the pathology is mild, patients are prescribed regular visits to a cardiologist, an ECG examination and an echocardiogram. Moderate aortic regurgitation is treated medically, the goal of therapy is to reduce the likelihood of damage to the aortic valve and the walls of the left ventricle.

First of all, prescribe drugs that eliminate the cause of the development of pathology. For example, if the cause is rheumatism, antibiotics may be indicated. As additional funds appoint:

  • diuretics;
  • ACE inhibitors - Lisinopril, Elanopril, Captopril;
  • beta-blockers - Anaprilin, Transicor, Atenolol;
  • angiotensin receptor blockers - Naviten, Valsartan, Losartan;
  • calcium blockers - Nifedipine, Corinfar;
  • drugs to eliminate complications resulting from aortic insufficiency.

In severe cases, surgery may be prescribed.. There are several types of surgery for aortic insufficiency:

  • aortic valve plastic;
  • prosthetic aortic valve;
  • implantation;
  • heart transplantation - performed with severe heart damage.

If aortic valve implantation has been performed, patients are prescribed lifelong use of anticoagulants - Aspirin, Warfarin. If the valve has been replaced with a prosthesis made of biological materials, anticoagulants will need to be taken in small courses (up to 3 months). Plastic surgery does not require these drugs.

To prevent relapse, antibiotic therapy, strengthening the immune system, as well as timely treatment of infectious diseases can be prescribed.

Forecasts and preventive measures

The prognosis for aortic insufficiency depends on the severity of the disease, as well as on what disease caused the development of pathology. Survival of patients with severe aortic insufficiency without symptoms of decompensation is approximately equal to 5-10 years.

The stage of decompensation does not give such comforting forecasts- drug therapy with it is ineffective and most patients, without timely surgical intervention, die within the next 2-3 years.

Measures to prevent this disease are:

  • prevention of diseases that cause damage to the aortic valve - rheumatism, endocarditis;
  • hardening of the body;
  • timely treatment of chronic inflammatory diseases.

Aortic valve insufficiency an extremely serious disease that should not be left to chance. Folk remedies can't help here. Without the right drug treatment and constant monitoring by doctors, the disease can lead to severe complications, up to death.

22162 0

Normally, the AK consists of three crescents. In 0.5% of the population, a congenital bicuspid valve is found, which is prone to degenerative changes with the development of a combined aortic defect in the form of regurgitation and stenosis (Fig. 1). In addition, these people have an increased risk of aortic dissection. A bicuspid valve can be diagnosed during routine echocardiography. In elderly patients, as well as in long-term arterial hypertension often there are focal sclerotic changes in the AC without significant obstruction. Minimal aortic regurgitation is also not uncommon, especially in the elderly.

Rice. 1. Typical view of congenital bicuspid AV (parasternal cross section). The arrow points to the round shape of the valve opening.

Aortic stenosis is the most common severe valvular heart disease in the European population, an indication for surgical treatment. The disease begins with focal sclerosis, which, spreading, leads to marked thickening, calcification, and immobility of the semilunar aortic cusps. These changes are well recognized by echocardiography. The presence of even mild aortic stenosis, in which only a slight acceleration of blood flow is noted (maximum velocity ‹2.5 m/s), leads to a distinct worsening of the cardiovascular prognosis. Severe aortic stenosis (aortic orifice area ‹1.0 cm2 or area index ‹0.6 cm2) requires careful assessment of clinical symptoms or signs of deterioration in LV function, the appearance of which becomes an indication for AV replacement. The most important echocardiographic parameters that characterize the severity of aortic stenosis are the average and maximum gradients on the aortic valve, as well as the area of ​​the aortic orifice, which is usually calculated using the blood flow continuity equation:

SAO = SLVOT × VTILVOT / VTI,

where SAO is the area of ​​the aortic orifice; SLVOT - cross-sectional area of ​​the LV outflow tract, calculated through its diameter D, as π × D2/4; VTILVOT - time integral of linear velocity in the outflow tract of the left ventricle (calculated in pulsed Doppler mode); VTI is the time integral of the linear velocity of blood flow through the AV (calculated in the constant wave Doppler mode; Fig. 2).

Rice. 2. A - the principle of the flow continuity equation. It follows from the law of conservation of mass that the product of the cross-sectional area and the average flow velocity or the integral of its velocity (v) is constant for each section of the pipe, which is reflected in the blood flow continuity equation in the upper left corner of the figure. The area of ​​the aortic orifice is calculated by solving the equation for CSA2.

B - an example of the use of the blood flow continuity equation in severe aortic stenosis.

I) Aortic stenosis (arrow) in parasternal longitudinal section; note concentric LV hypertrophy.

II) Magnified image of the AV region with measurement of the LV outflow tract diameter (D) at a distance of 2 cm from the AV annulus.

III) Recording of blood flow in the outflow tract of the left ventricle in pulsed Doppler mode with the calculation of the integral of velocity over time (VTILVOT).

IV) Recording of blood flow through the AK in constant-wave Doppler mode with the calculation of the integral of velocity over time (VTIAS). From the blood flow continuity equation, the area of ​​the aortic orifice (A) is calculated by the formula: A = π × (D2/4) × VTILVOT / VTIAS, which is 0.6 cm2 and corresponds to severe stenosis.

Sometimes, especially with transesophageal echocardiography, the area of ​​the narrowed aortic orifice can be determined directly by the planimetric method. It must be remembered that the area of ​​the aortic orifice does not depend on SV, therefore, in case of LV dysfunction, it remains the only reliable indicator for assessing the severity of aortic stenosis.

Sometimes, in the case of severe LV dysfunction and suspected severe aortic stenosis, stress echocardiography with dobutamine helps clarify valve function and prognosis.

Among all valvular defects, aortic regurgitation is the most difficult for EchoCG assessment of its severity. Causes of aortic regurgitation can be expansion of the ascending aorta (for example, in Marfan syndrome), valve calcification, infective endocarditis, degenerative changes such as prolapse, rheumatic disease, etc. Semiquantitatively, the severity of aortic regurgitation can be assessed in the following ways(Fig. 3):

  • assessment of valve morphology and degree of LV enlargement;
  • determination of the ratio of the width of the base of the regurgitation jet to the diameter of the LV outflow tract in the parasternal longitudinal section (≥65% is a sign of severe regurgitation);
  • calculation of the half-decay time of the pressure gradient between the aorta and the left ventricle according to the flow of aortic regurgitation recorded in the constant-wave Doppler mode (half-decay time of the pressure gradient ‹250 ms - feature severe regurgitation);
  • registration of holodiastolic reverse blood flow in the descending aorta (from the supraclavicular approach) with a speed at the end of diastole >16 cm/s indicates severe regurgitation.

Rice. 3. Aortic regurgitation.

A - parasternal longitudinal section: the jet of regurgitation (in diastole) occupies the entire LV outflow tract.

B - enlarged transesophageal image of the AC along the long axis: prolapse of the non-coronary aortic crescent (arrow).

C - aortic regurgitation in constant wave Doppler mode. The white line indicates the slope corresponding to the decrease in the diastolic rate of aortic regurgitation, which can be used to determine the half-life of the pressure gradient between the aorta and the left ventricle.

D - pulsed Doppler study of blood flow in the descending aorta from the supraclavicular approach: a distinct holodiastolic reverse flow (the arrow indicates reverse blood flow continuing until the end of diastole). BoA - ascending aorta.

An important part of the examination of patients with moderate and severe aortic regurgitation is the assessment of LV functions (size and EF) and the diameter of the ascending aorta.

Signs of AK damage in infective endocarditis are vegetations, newly appeared aortic regurgitation, structural defects of the semilunar valves and the transition of the process to perivalvular tissues with the formation of para-aortic abscesses and fistulas (for example, between the aortic root and LA). Such complications are especially well recognized during transesophageal examination.

Frank A. Flachskampf, Jens-Uwe Voigt and Werner G. Daniel