Coarctation of the aorta - Causes, Symptoms and Treatment .MF .
coarctation of the aorta is a congenital malformation characterized by segmental (local) narrowing of the lumen of the aorta or its complete break in the Isthmus of her arc, much less in the thoracic or abdominal her department.Coarctation of the aorta, strictly speaking, is not a congenital defect of the heart, as it is localized, affecting the aorta - the largest gypsy arterial vessel systemic circulation, extending from the left ventricle of the heart.The structure of the heart with this congenital pathology is normal.And yet, coarctation of the aorta always belong to the group of congenital heart defects, since it suffers the entire circulatory system (cardiovascular system), and the formation of the aortic coarctation is directly related to the structure of the heart and can be combined with some other congenital malformations it.Coarctation of the aorta was first described in 1791 by the Italian pathologist D. Morgan.
coarctation of the aorta is usually located in a specific, typical for her plac
Schematic representation of the aortic coarctation
frequency of this congenital defect ranges from 6.7 to 15% of all congenital heart defects, and in 3-5 times more common in male subjects than in female.
There are two types of aortic coarctation:
1) "adult" type of aortic coarctation - there is a segmental narrowing of the lumen of the aorta below (down the blood flow), the place where it departs from the left subclavian artery;ductus arteriosus while closed;
2) "Child" (infantile) type of aortic coarctation - there hypoplasia (underdevelopment) of the aorta in the same place, but the ductus arteriosus open.
In addition, depending on the anatomical features are three different versions of coarctation:
1. An isolated coarctation of the aorta (without combination with other congenital heart defects);
2. aortic coarctation, combined with patent ductus arteriosus;in turn, can be subdivided:
• postduktalnaya (located below the point where departs patent ductus arteriosus);
• yukstaduktalnaya (coarctation is located at the level of the ductus arteriosus);
• preduktalnaya (patent ductus arteriosus coarctation of the aorta is opened below).
3. aortic coarctation, combined with other congenital heart disease: atrial septal defect (ASD), ventricular septal defect (VSD), aneurysm of sinus of Valsalva, transposition of the great vessels, aortic stenosis, and others.
ductus arteriosus detected in more than 60% of infants with coarctation of the aorta, with the diameter of the duct may be larger than the diameter of the aorta.Isolated coarctation of the aorta is more common in older children.
below (down the blood flow) of the aortic narrowing its wall space thinned, and the lumen is extended, sometimes assuming the character of an aneurysm of the aorta (aortic enlargement area due to pathological changes of connective tissue structures of its walls).Aneurysmal changes occur as a result of exposure to the aortic wall turbulent (chaotic) blood flow below the constriction.In older children and aneurysmal changes develop higher contraction - in the ascending aorta.
When atypical localization of coarctation of the aorta, it is located in the thoracic or abdominal her department.Sometimes it can occur and multiple contractions.
There are also 'aortic psevdokoarktatsiyu "- similar to the aortic coarctation deformation, not pose a significant obstacle to blood flow, because it is a simple tortuosity and elongation of the aorta.
causes of aortic coarctation
development of coarctation of the aorta due to a violation of the formation of the aorta in utero.Most often, coarctation of the aorta is yukstaduktalnoy (located on the ductus arteriosus level. Ductus arteriosus which connects the aorta to the left pulmonary artery, which normally operates only in utero and after birth of the child and the beginning of the alveolar breath is closed. Apparently, in utero somepart of the fabric duct is moved to the aorta, thereby bringing into the process of its closure, and aortic wall, which subsequently leads to its contraction.
in some rare cases, coarctation of the aorta may occur throughout life as a result of atherosclerotic lesions of the aorta, aortic or syndrome injury Takayasu (inflammatory disease of unknown origin, damaging the aorta and its branches).
Genetic predisposition to the formation of coarctation of the aorta is present in patients with the syndrome Shereshevskii-Turner (chromosomal disease, caused by the presence of only one sexual X-chromosomes and the absence of a second and is accompanied by characteristic abnormalities of physical development,short stature and sexual immaturity).Every tenth patient with this syndrome revealed coarctation of the aorta.
mechanism of violation of hemodynamics (blood flow)
If aortic coarctation presence of mechanical obstruction (the so-called gateway) in the path of blood flow in the aorta leads to the formation of two different modes of circulation.Higher blood flow obstruction blood pressure places increased, and the bloodstream is extended;the left ventricle due to systolic (the phase of the heartbeat) overload hypertrophy (increase his muscle mass and size).The following places obstacles current blood pressure is lowered and blood flow compensation is due to the development of multiple ways to bypass (collateral) blood supply.Hemodynamic severity varies depending on the extent and severity of the narrowing of the aortic lumen, as well as the type of coarctation.
When "adult" type of coarctation, when the ductus arteriosus zaraschёn (closed), the major hemodynamic disorder associated with increased blood pressure in the vessels of the upper body, while increased and systolic and diastolic blood pressure.This hypertension is accompanied by a sharp increase produced by the left ventricle of the heart, as well as an increase in the mass of circulating blood.At the same time in the lower half of the trunk artery pressure is reduced, because of which included a mechanism for increasing the renal blood pressure, which leads to an even greater increase in pressure in the upper half of the body.
When "child" type of coarctation of the aorta when the ductus arteriosus open, high blood pressure in the vessels of the systemic circulation may not be as advanced as collateral (bypass) the blood circulation is poorly developed.Depending on the relationship of coarctation, and patent ductus arteriosus, there are differences in the mechanisms of hemodynamic instability.So, when postduktalnoy coarctation of the aorta occurs discharge of blood under high pressure from the aorta through the ductus arteriosus in the left pulmonary artery, which may soon lead to the development of pulmonary hypertension (increased blood pressure in the vessels of the pulmonary circulation).
When preduktalnom version of coarctation of the aorta is characterized by discharge of blood from the pulmonary trunk to the descending aorta (below the coarctation) through the ductus arteriosus, however, subject to the availability of well-developed collaterals can be reset in the opposite direction - from the descending aorta to the patent ductus arteriosus and a small circlecirculation.In that situation, when at preduktalnom embodiment coarctation has a discharge from the pulmonary artery to the descending aorta, almost all of minute volume of blood for Mologa circulation, as well as for the lower half of the body is provided by the increased work of the right ventricle of the heart."Children" (infantile) type of coarctation of the aorta leads to disruption of the pulmonary circulation, and in most cases, already in early childhood - to the development of heart failure.
Symptoms of aortic coarctation
clinical picture of coarctation of the aorta is determined primarily by age, morphological changes, combined with other heart defects.
In early childhood this defect quite often accompanied by recurrent (repeated), pneumonia, development of the first days of life of lung-heart failure.Characterized by sudden paleness of skin, dyspnea, wheezing accompanied by stagnation in the lungs.Children with aortic coarctation often lag behind in physical development.
Determined expansion of the heart borders and increased apical impulse.Auscultation (listening to) the heart doctor detects a rough tone systolic (between heart beats) noise at the front of the chest in the projection base of the heart or on the back surface in the interscapular region to the left (which is projected onto the isthmus of the aorta).In the presence of patent ductus arteriosus doctor listens systolic noise in the second intercostal space to the left of the sternum.Also, there is a growing II heart sound over the pulmonary artery and the aorta.
decisive role in the initial diagnosis of coarctation of the aorta heart plays a character on the upper and lower extremities: a combination of intense pulse on arteries in the elbow with no or a sharp weakening of the femoral pulse.
When preduktalnom variant of aortic coarctation with discharge from the pulmonary artery to the descending aorta (venoarterialny reset) at the same time weakening the pulse on his feet is determined the so-called differential cyanosis: leg skin with cyanosis normal color of the skin of hands.In children with a pronounced and isolated (not combined with other congenital heart defects), coarctation of the aorta blood pressure measured on the hands can reach very high values, up to 190-200 / 90-100 mm Hg.Art.In the case of a combination of coarctation of the aorta with other congenital heart defects measured on their hands the blood pressure reaches 130-170 / 80-90 mm Hg.Art., very rarely it is normal.Arterial pressure on the feet is not detected at all or drastically reduced.Possible difference raterialnogo pressure on the hands (in the case of abnormal discharge of the right subclavian artery from the descending aorta).The children of the first years of life, heart failure develops in both the systemic circulation.
In adults and older children in those cases where there are no complaints, high blood pressure often found by accident.These patients complain of dizziness, headaches, heaviness in the head, fatigue, recurrent epistaxis, in some cases - heart pain.At the same time, patients complain of pain in the legs, and weakness in them, muscle cramps in the legs, chilly feet.Women may experience menstrual irregularities and infertility.In general, the normal physical development marked a disproportionate development of muscles: the muscles of the upper half of the trunk and upper limbs developed too, and pelvic muscles and the lower limbs are underdeveloped.The feet are cold to the touch.It determines the gain ripple intercostal arteries.Measured on hands systolic blood pressure by 50-60 mm Hg.Art.exceeds the systolic pressure on the legs, at normal pressure on the legs should be higher.The diastolic pressure remains normal.Do older children usually do not have a heart failure: it develops after 20-30 years, as a poor prognostic sign.
Complications of aortic coarctation:
1. Severe hypertension;
2. Intracerebral hemorrhage (stroke);
3. Subarachnoid hemorrhage;
4. Left ventricular heart failure with cardiac asthma and pulmonary edema;
5. Hypertensive nefroangioskleroz (loss of arterioles (small arteries), kidney with hypertension, gradually leading to the development of so-called primary contracted kidney);
6. Breaks Extended aneurysm;
7. Infective (Bacterial) Endocarditis - endocardial damage (inner lining of the heart) and the heart valve, caused by an infection (usually bacterial).The development of infective endocarditis is more common in the combination of aortic coarctation with congenital pathology of the aortic valve (eg, the presence of bicuspid aortic valve).Bacterial endocarditis in aortic coarctation is often resistant to the use of antimicrobials.
1. Electrocardiography (ECG): In case of no moderate aortic coarctation electrocardiogram practically different from the normal electrocardiogram.The children of the first years of life in the case of a combination of coarctation of the aorta with patent ductus arteriosus and ventricular septal defect is marked displacement (deviation) of the heart's electrical axis (EOS) to the right or its vertical position, and there are signs of increasing muscle mass (hypertrophy) of both ventricles of the heart, moredegree right.For patients electrocardiogram older children characterized by isolated signs of increased muscle mass of the left ventricle.In adult patients with coarctation of the aorta detected offset heart's electrical axis to the left, and signs of increased muscle mass of the left ventricle of the heart, can also be determined by incomplete blockade of the left bundle branch block.
2. phonocardiography (recording vibrations and sound signals produced when the activity of the heart and blood vessels).When phonocardiography fixed amplification II tone of the aorta, a diamond Peak-systolic murmur in the second and third intercostal space at the left edge of the sternum in the second intercostal space at the right edge of the sternum, as well as on the back.
3. Echocardiography (ultrasound of the heart) can detect narrowing of the aorta in the region of its isthmus.Doppler echocardiography makes it possible to identify the characteristic signs of coarctation: turbulent systolic flow below the constriction, the difference in systolic blood pressure between the aorta to the restriction and its lower part narrowing.Also identified indirect echocardiographic (sonography) signs of coarctation of the aorta: increasing muscle mass (myocardial hypertrophy) of the left ventricle, the increased mobility of the rear wall, the increase in left atrial size.
4. Chest X-ray (heart and lungs).Pulmonary pattern without pathological changes, with postduktalnoy coarctation or in the case of a combination with a ventricular septal defect is reinforced by the arterial bed.Heart Shadow has a spherical shape, the tip of its elevated, and the ascending aorta is enlarged.Patients older children heart of normal size or slightly enlarged left, moreover, determined uzuratsiya ( "corroded") of the lower edges of the rear parts of the ribs due to the deepening of the rib grooves on the inner surface of the ribs to the pressure extended tortuous intercostal arteries.
5. Cardiac catheterization is performed to measure the pressure in the aorta and reveals a characteristic feature of coarctation of the aorta - the difference in systolic blood pressure above and below the current space narrowing of the aorta blood.
6. Aortography (introduction of radiopaque substance into the aorta through special catheters) makes it possible to directly determine the level and degree of narrowing of the aortic lumen.
Aortogramma patients with coarctation of the aorta, made in a right oblique projection: arrow Set complete break shade zakontrastirovannoy aorta in its isthmus.
Treatment of aortic coarctation
indication for surgery for aortic coarctation is a difference in systolic pressure, measured on hands and feet, exceeding 50 mm Hg.Art.In newborns and infants the basis for the implementation of operative intervention can serve as severe hypertension and cardiac decompensation.In cases when the disease has a relatively favorable course, surgery deferred until 5-6 years of age.Carrying out of surgery and at a later date, however, due to the ability to save after her hypertension worse its results.
Surgeon Kletkin ME