Coarctation of the aorta: symptoms, diagnosis, treatment

Coarctation of the aorta is a limited narrowing of the aortic lumen, which leads to upper limb hypertension, left ventricular hypertrophy and hypoperfusion of the abdominal cavity organs and lower limbs. Symptoms of coarctation of the aorta vary depending on the degree of narrowing and its extent - from headache, pain in the chest, cold extremities, weakness and lameness to fulminant heart failure and shock. Soft noise can be heard over the place of constriction. The diagnosis is based on echocardiography or CT or MR angiography. Treatment of aortic coarctation - balloon angioplasty with stenting or surgical correction. It is recommended to prevent endocarditis.

Coarctation of the aorta is 8-10% among all congenital heart defects. It is noted in 10-20% of patients with Shereshevsky-Turner syndrome. The ratio of boys and girls is 2: 1.

Coarctation of the aorta usually develops in the proximal part of the thoracic aorta immediately below the site of the subclavian artery. Coarctation of the abdominal aorta is rare. Coarctation can be an isolated defect or be combined with other congenital anomalies (for example, the bicuspid valve of the aorta, the defect of the interventricular septum, the stenosis of the aorta, the open arterial duct, the anomalies of the mitral valve, aneurysms of the brain).

Physiological consequences include increased pressure load on the left ventricle, hypertrophy of the left ventricle, hyperperfusion of the upper half of the body, including the brain, and hypoperfusion of the abdominal cavity organs and lower limbs.

[1], [2], [3], [4], [5]

Symptoms of coarctation of the aorta

There are probably two variants of coarctation of the aorta:

• isolated coarctation (adult type);
• coarctation of the aorta in combination with the open arterial duct, the aortic constriction is located pre- or post-positive (children's type).

Children's type of coarctation is most unfavorable, as it is accompanied by very early formation of high pulmonary hypertension. Constriction of the aorta blocks the blood flow from the heart to the organs of the lower half of the body, as a result of which the arterial pressure rises above the site of constriction. This leads to the formation of physique - "athletic" physique with a well-developed shoulder girdle, as well as to the appearance of complaints typical of hypertension (headaches, nosebleeds). In the natural course of the defect, morphological changes in the coronary arteries, secondary fibroelastosis of the left ventricle endo- and myocardium, cerebral circulation disorders or cerebral hemorrhages may develop, which also worsens the results of delayed surgical treatment.

With a significant narrowing in the period of newborns, circulatory shock with renal insufficiency (oliguria or anuria) and metabolic acidosis may develop, resembling a clinic of other systemic diseases, for example sepsis.

Less pronounced narrowing may not appear clinically in the first year of life. Nonspecific symptoms of coarctation of the aorta (for example, headache, chest pain, weakness and lameness during exercise) may appear as the child grows. Often there is hypertension, but heart failure rarely develops after the neonatal period. Rarely there is an aneurysm rupture of the brain, which leads to subarachnoid or intracranial hemorrhage.

Typical results for physical examination are hypertension of the vessels of the upper extremities. The pulse on the femoral artery is weak or lagging, low or undetectable BP on the lower extremities. Systolic murmur of intensity ejection 2-3 / 6 is best heard in the interblade area on the left. Expanded intercostal collateral arteries can lead to the appearance of prolonged noise in intercostal space. Girls with coarctation of the aorta may have Turner syndrome, a congenital disease in which lymphatic leg edema develops, pterygopodia on the neck, square chest, cubitus valgus, widely spaced nipples.

In the absence of treatment in adulthood, left ventricular heart failure, aortic rupture, intracranial hemorrhage, hypertensive encephalopathy and hypertension can develop.

Diagnosis of aortic coarctation

The diagnosis is based on clinical data (including measurement of blood pressure on all 4 limbs), taking into account chest X-ray and ECG, an accurate diagnosis is established based on two-dimensional echocardiography with color Dopplercardiography or CT or MR angiography.

Clinical diagnosis of coarctation of the aorta is specific, the characteristic symptoms attract attention even at the first examination. The area of the heart is not visually changed. The boundaries of relative cardiac dullness are not expanded. An intense systolic murmur is heard on the basis of the heart, a point of maximum listening is between the shoulder blades at the level of the second thoracic vertebra. The pulse on the femoral artery is weakened or not palpable. Arterial pressure on the legs is significantly reduced or not determined. If the defect is first diagnosed at the age of more than 1 year, this indicates its relatively low severity. Expressed coarctation of the aorta manifests itself in the first months of life by anxiety, poor weight gain, lack of appetite. Since the measurement of blood pressure in infants is difficult, in the examination necessarily determine the pulse on the femoral arteries and evaluate its characteristics.

The ECG usually shows left ventricular hypertrophy, but the ECG can be normal. In newborns and children of the first months of life, ECG is more likely to display right ventricular hypertrophy or blockade of the right leg of the bundle of the Hisnia than left ventricular hypertrophy.

Radiographically, it is possible to identify the usurpation of the lower edges of the ribs due to the pressure of sharply expanded and convoluted intercostal arteries. The heart can have a globular or "aortic", ovoid configuration with a raised apex. Radiography of the thoracic organs demonstrates coarctation in the form of a "3" sign in the region of the shade of the superior anterior mediastinum. The size of the heart is normal, unless heart failure develops. Expanded intercostal collateral arteries can usurize the 3rd to 8th ribs, as a result of which ribs appear in the lower contour region, while ribbon usury is rarely formed before the age of 5 years.

When scanning the aorta, a suprasternal position is used. Indirect echocardiographic signs confirming coarctation - poststenotic enlargement of the aorta, hypertrophy and dilatation of the ventricles.

Cardiac catheterization and angiocardiography are indicated in cases where the nature of concomitant heart defects is not clear or there is a suspicion of aortic arch break.

Differential diagnosis is performed with all conditions accompanied by increased blood pressure. In favor of coarctation of the aorta indicates a significant weakening or lack of pulse on the femoral arteries. Similar clinical signs may be in nonspecific aorto-arteritis, a disease of an autoimmune nature, in which a proliferative process develops on the inner shell of large vessels, as a result of which the lumen of blood vessels decreases and blood pressure rises. Because of asymmetric vascular lesions, nonspecific aorto-arteritis is called "a disease of a different pulse".

[6], [7], [8]

Treatment of coarctation of the aorta

Treatment operative. In children of the first months and years of life, the disorder is severe because of the small number of collaterals, which makes it necessary to perform early surgical intervention. If the course of the defect is not severe. To avoid recoarction in the correction site, it is better to postpone the operation to 6-14 years. Surgical treatment consists of a resection of the narrowed aorta and the imposition of a synthetic patch on this site.

Newborns in the presence of clinical manifestations need stabilization of cardiac pulmonary disorders, which is usually done by infusing prostaglandin E1 [0,05-0,10 mkg / (kg x min), then reducing to the lowest effective doses] in order to open the arterial duct. After that, blood from the pulmonary artery can enter the descending aorta through the duct, improving systemic perfusion and preventing the development of metabolic acidosis. Short-acting inotropes (eg, dopamine, dobutamine), diuretics and O2 are used to treat heart failure.

Before the correction for the treatment of hypertension, blockers can be used; the use of ACE inhibitors should be avoided. After surgery, blockers, ACE inhibitors or angiotensin II receptor blockers are used to correct hypertension.

Disadvantageous is the question of the preferred method of radical correction of the defect. In some centers, balloon angioplasty is preferred with or without stenting, but others prefer surgical correction and leave balloon angioplasty for recoarction after surgical correction. The initial frequency of successful correction after balloon angiography is 80-90%; with subsequent catheterizations, the stent can expand as the child grows.

Operations for correction of coarctation include resection and application of an anastomosis end-to-end, aortoplasty by patch and aortoplasty with a patch from the left subclavian artery. The choice depends on the anatomy of the blemish and the preferences of the center. Surgical lethality is less than 5% in the presence of clinical manifestations in infants and less than 1% in older children. Often residual coarctation remains (6-33%). Rarely develops paraplegia as a result of clamping the aorta during surgery.

All patients, regardless of whether a correction of the defect was performed or not, should receive endocarditis prophylaxis before dental or surgical procedures in which bacteraemia may develop.