What is aortic insufficiency?
Author Ольга Кияница
Aortic insufficiency (AN), a form of valvular heart disease, which is still known as aortic regurgitation.Occurs when the aortic valve of the heart is not tightly closed, which leads to the flow of blood in the wrong direction (reflux). As a result, the heart can not work effectively, contributing to the appearance of clinical signs by type of fatigue and dyspnea. Sometimes, AN goes on for many years and does not show any symptoms. Also, pathology can develop rapidly and suddenly.
There are many reasons for the development of aortic insufficiency, but most often pathology is associated with congenital malformations and rheumatic heart disease.
The disease can occur in acute and chronic form. In the latter case, the symptoms can hardly be manifested, and the disease itself has been developing for many years. Depending on the form of AN, appropriate treatment is carried out, which allows improving the condition and quality of life of the patient.
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All over the world, the most common cause of AS is rheumatic heart disease. Congenital and degenerative valvular anomalies are most common among the causes of the disease in the United States, which is more often defined in 40-60 years. Estimates of prevalence of AN of any severity range from 2 to 30%, but only 5-10% of patients with AS have a severe course of the disease, as a result of which the overall prevalence of severe AS is less than 1% in the general population. [1 - Maurer G. Heart. Aortic regurgitation. 2006; 92 (7): 994-1000.]
In the Framingham study (5209 patients aged 28-62 years in the main group and 5 512 patients in the additional group), AN of any severity was detected in 13% of men and 8.5% of women. [2 - Singh JP; Evans JC; Levy D; Larson MG;Freed LA; Fuller DL; Lehman B; Benjamin EJ. Prevalence and clinical determinants of mitral, tricuspid, and aortic regurgitation (the Framingham Heart Study). Am J Cardiol. 1999; 83 (6): 897-902]
Aortic insufficiency is more common in men than in women. In the Framingham study group, AI was found in 13% of men and 8.5% of women. The higher prevalence of AH in men may partly reflect the predominance of underlying conditions, such as Marfan syndrome or the bicuspid aortic valve in men.
Chronic aortic regurgitation often begins in patients when they reach the age of 50 and are most frequently recorded in patients older than 80 years. In general, the prevalence and severity of AS increase with age, although severe chronic AN is rare up to 70 years.
Any condition that damages the aortic valve can cause regurgitation. Among all the reasons for the return of blood through the aortic valve, the following most often distinguish:
- Congenital heart defect . The patient can determine one valve leaf (single-leaf aortic valve) or two valves (a two-winged aortic valve), instead of the normal three valves.
- Deterioration of the valve with age . The aortic valve opens and closes tens of thousands of times a day over many years of life, so aortic valve failure may be due to its wear and tear.
- Endocarditis . The aortic valve is damaged by endocarditis, an infection that affects the internal parts of the heart, including its valve apparatus.
- Rheumatic fever . This disease is a complication of sore throat with the participation of streptococcus. Often against the background of its course, the aortic valve is damaged, which leads to its failure in the future.
- Other reasons . Rare conditions that can damage the aortic valve and lead to regurgitation include Marfan syndrome (connective tissue disease), ankylosing spondylitis (spinal disorder), and syphilis (sexually transmitted disease).Damage to the aorta near the aortic valve site, such as a chest trauma or aortic aneurysm, can also lead to a reverse blood flow through the valve.
When the aortic valve is functioning normally, it opens only when the pressure in the left ventricle (LV) is greater than the pressure in the aorta. This allows you to release blood from the heart cavity into a large vessel during ventricular systole.After the contraction, the pressure in the ventricle gradually decreases, on the background of which it relaxes and prepares to take a new portion of blood from the left atrium. When the pressure in the LV drops below the pressure in the aorta, the aortic valve closes, preventing the return of blood.
With aortic regurgitation, when the pressure in the left ventricle falls below the pressure in the aorta, the aortic valve can not completely close. This leads to a return of blood from the aorta to the left ventricle. This means that part of the blood that has already been pushed out of the heart chamber returns.
The percentage of blood that left the left ventricle and returned back through the aortic valve due to aortic insufficiency is called the regurgitation fraction.
The regurgitation fraction in the AS can be of three degrees of severity:
- The heavy fraction of regurgitation is above 40%
- Moderate fraction of regurgitation - from 20% to 40%
- Minor regurgitation - up to 20%
Calculate the fraction of regurgitation by means of ventriculography.
The regurgitation flow reduces the diastolic blood pressure in the aorta and, therefore, contributes to an increase in pulse pressure (one of the components of blood pressure), which is the difference between systolic and diastolic pressure.
Aortic insufficiency causes both an overload volume (increase in preload), and pressure (increased afterloading).
Pressure overload caused by high impulse pressure and hypertension leads to hypertrophy of the left ventricle, which, with aortic regurgitation, is more often defined as concentric and eccentric. Concentric hypertrophy is caused by hypertension associated with aortic insufficiency, whereas eccentric hypertrophy is caused by the volume of overload caused by the regurgitation fraction. Hypertrophy and dilatation of the left ventricle with chronic aortic insufficiency is an ineffective mechanism of compensation and, therefore, causes a large number of symptoms in the patient.
The hemodynamic complications of aortic insufficiency depend on the rate of development of the disorder. Acute and chronic form of AN will have a different hemodynamics, and patients often provide various signs and symptoms.
Acute aortic insufficiency
In acute AH, observed in the perforation of the aortic valve against the background of endocarditis, there is a sharp increase in the volume of blood in the left ventricle. LV, unable to cope with sudden hemodynamic overload, is decompensated, which leads to an increase in pressure in the left atrium, which causes the patient to develop congestive heart failure. This condition increases the pressure in the left atrium, which leads to stagnation of blood in the pulmonary veins, hypertension in the pulmonary circulation, the development of symptoms of congestive heart failure with severe dyspnea.
Severe acute aortic regurgitation requires urgent medical attention. There is a high risk of mortality when the patient does not undergo immediate surgery to replace the aortic valve. If the acute AS is caused by the endocarditis of the aortic valve, there is a possibility that the new valve will be a source for further infection of the patient.
Chronic aortic insufficiency
If the patient survives after acute AS, the left ventricle adapts to the new state with the help of eccentric hypertrophy or dilatation, which makes it possible to compensate for the volume of overload. The pressure of filling the left ventricle returns to normal values, and the patient does not develop heart failure.
In this compensated phase, the patient may completely have no symptoms, including tolerance to the usual exercises.Nevertheless, in the absence of treatment and after a more or less prolonged period of time, usually after a long latent course of the disease, the left ventricle again decompensates, and the filling pressure increases. In such cases, most patients develop symptoms of a congestive heart, although sometimes in patients with chronic AS continues to have a decompensated asymptomatic phase. Treatment of AN by replacing the aortic valve should be performed before the decompensation stage.
Most often, regurgitation of the aortic valve develops gradually, because the heart compensates the problem. For many years, there may be no signs and symptoms in the patient. However, with the development of aortic regurgitation, the following manifestations usually occur:
- Fatigue and weakness, especially when the level of activity of the patient increases
- Dyspnoea, especially with tension or lying down
- Chest pain, discomfort or constriction in the heart area, often increasing during exercise
- Fainting condition
- Fast or irregular heartbeat
- Palpitation - a feeling of rapid heartbeat, its flutter (atrial fibrillation)
- Swollen ankles and legs
In addition, physiological examination of the patient can determine the following symptoms:
- The jumping pulse , or "water hammer pulse," characterized by a rapid and sharp decrease in diastolic pressure, which becomes more noticeable when the patient raises his forearms above the heart.
- Corrigan's pulse : determined on the carotid artery and characterized by rapid expansion or rise of the pulse wave followed by a sharp decrease in it.
- Symptom Musset : a rhythmic oscillation of the patient's head is noted, corresponding to the rhythm of heartbeat.
- Symptom Quincke (still known as a capillary pulse): pulsed staining of the nail bed with not strong pressure on its end,
- Symptom Durozier : double aortic noise, which sounds like a pistol shot on the femoral artery, when it is pressed with a stethoscope, is determined in both systole and diastole.
- Traube Symptom : A double sound that is heard over the femoral artery when distal pressure is applied to the vessel.
- Symptom of Rosenbach : a pulsating liver is detected
- A symptom of Gerhard , a pulsating spleen is determined.
Other signs of this diverse semiology include the Landolpie symptom (constriction and alternation of pupil dilatation), the Becker symptom (retinal vascular pulsations), the Mueller symptom (tongue pulsation), the Maya symptom (a drop in arterial pressure by more than 15 mmHg when the arm is raised) and the Hill symptom (the difference in popliteal and humeral pressure is more than 20 mm Hg).
None of the above signs is sufficient to establish the correct diagnosis of aortic insufficiency. An important clinical significance is diastolic noise with or without these symptoms.
In addition to physical examination, the most common test used to assess the severity of aortic insufficiency is echocardiography , which provides two-dimensional (and sometimes three-dimensional) images to study the size, shape, and movement of blood flow to the heart, and the workings of its valves. With aortic regurgitation, it is possible to measure the speed (usually
Electrocardiography can show left ventricular hypertrophy, if there is one due to diastolic overload, which leads to increased tension in the left heart.
Radiography of the chest and is performed to assess the size of the left ventricle.
Laboratory tests can help to exclude other cardiac and systemic pathologies that cause signs and symptoms similar to the clinical picture of AN.
Aortic insufficiency can be treated by a medical or surgical method, depending on the severity of the disease, the symptoms associated with the process of the disease, and the degree of left ventricular dysfunction.
Surgical treatment is usually necessary if the left ventricular ejection fraction falls below 55% or when the size of the left ventricle increases by more than 55 mm, regardless of the symptoms. If any of these indicators is significantly impaired, the forecast, as a rule, tends to deteriorate.
It is most often used to improve the condition of patients on chronic aortic insufficiency. Includes the use of vasodilators, ACE inhibitors, nifedipine, and hydralazine to improve the condition of the left ventricular wall, ejection fraction and to maintain the structure of the ventricle. The purpose of using these pharmacological drugs is to reduce the load before, the possible condition, to protect the left ventricle.
The regurgitation fraction may not change significantly, because the gradient between aortic and ventricular pressures is usually small at the beginning of the treatment. The use of these vasodilators is indicated only in patients who, in addition to AN, have hypertension.
Surgical treatment of AS is the replacement of the aortic valve. At the moment this operation is carried out on an open heart, therefore it is required that a person be connected to the cardiopulmonary apparatus. In the absence of absolute contraindications to all persons with severe acute AN, an operation is performed. Those who have a complication in the form of bacteremia with aortic valve endocarditis should not expect that antibiotic treatment will begin to work, as the death rate associated with this form of AN is very high.
In the future, aortic valve replacement is expected by a percutaneous route.
Preventive measures for aortic insufficiency are mainly associated with preventing the development of infectious and rheumatic endocarditis. In other cases, aortic insufficiency is an insurmountable disease, although some of its complications, under favorable conditions, can still be prevented from developing.
When confirming the diagnosis of aortic insufficiency, a cardiologist may limit certain types of physical activity.Pregnancy usually does not carry serious risks, unless the AH is in a difficult phase of development. Also, if the patient undergoes a heart transplant or if he takes certain medications related to AN, it may be necessary to consult a cardiologist before considering the possibility of becoming pregnant
The prognosis for patients with severe AS depends on the presence or absence of LV dysfunction and symptoms. In the asymptomatic course of the disease with a normal ejection fraction, the following was found:
- The rate of progression of symptoms or LV dysfunction is less than 6% per year
- The rate of progression to asymptomatic LV dysfunction is less than 3.5% per year
- The rate of sudden death is less than 0.2% per year
- In asymptomatic patients with a decrease in the ejection fraction, the rate of progression of symptoms exceeds 25% per year, whereas in patients with signs, the mortality rate is more than 10% per year.
The strongest predictors are echocardiographic parameters (end systolic evaluation and left ventricle), which emphasizes the crucial role of serial echocardiography in the treatment of patients with severe AS.
The determination of the final systolic index of the left ventricle can have prognostic significance as an independent predictor of results in patients with asymptomatic moderate or severe AN.
Severe acute AS, if left untreated, can lead to significant morbidity and mortality from the underlying cause (usually infective endocarditis or aortic dissection) or from hemodynamic LV decompensation.
Potential complications in patients with severe chronic AH include progressive LV dysfunction and dilation, congestive heart failure, myocardial ischemia, arrhythmia and sudden death. Additional complications can result from the patient's underlying condition (for example, dissection of the aortic root in a patient with a bicuspid aortic valve and a strongly dilated aortic root).
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