Open arterial duct: symptoms, diagnosis, treatment
Last reviewed: 23.04.2024
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The arterial (botalla) duct is a necessary anatomical structure, providing together with the oval window and arantium duct the embryonic type of the fetal circulation. An open arterial duct is a vessel that connects the thoracic aorta to the pulmonary artery. Normally, the function of the arterial duct stops after a few hours (no more than 15-20) after birth, and the anatomical closure continues for 2-8 weeks. The duct becomes an arterial ligament. If the duct does not close, the blood from the aorta is discharged into the pulmonary artery, the pressure in the small circle of blood circulation rises. The discharge of blood occurs in both phases of the cardiac cycle, since both in systole and in diastole, the pressure in the aorta is significantly higher than in the pulmonary artery (a pressure gradient of at least 80 mm Hg).
[Symptoms of open ductus arteriosus
When palpation is determined, systolic jitter at the base of the heart on the left. Percutorno - widening the boundaries of relative cardiac dullness to the left. Features of hemodynamics are the basis of the main clinical symptom of this defect - sonorous continuous systolo-diastolic noise in the second intercostal space on the left (noise of "mill wheel", "machine noise"). However, in the pathological opening of the duct, at first (in the first week) there is only systolic noise, since the pressure difference in the small and large circles of the circulation in this period is small, and the cross-discharge occurs only during the systole period. As the development of pulmonary hypertension, the noise becomes intermittent (systolic and diastolic), then the diastolic component disappears. Accordingly, the increase in pressure in a small circle of circulation increases the accent of the second tone over the pulmonary artery. If timely operational assistance is not provided, systolic murmur at the apex may appear, indicating a "mitralization" of the defect, that is, the formation of a relative mitral valve insufficiency. As a manifestation of heart failure with a large discharge from left to right, tachypnea appears. Stagnant rales in the lungs, enlargement of the liver and spleen.
The frequency of occurrence of the open arterial duct is 6-7%. In 2-3 times more often the anomaly is observed in girls.
How to recognize the open arterial duct?
The ECG makes it possible to detect the deviation of the electric axis of the heart to the left, signs of an overload of the left ventricle. There are changes that characterize the disturbance of metabolic processes in the myocardium of the enlarged left ventricle (negative T in the left thoracic leads).
X-ray reveals augmentation of the pulmonary pattern, corresponding to the value of arteriovenous discharge, expansion or swelling of the pulmonary artery. The waist of the heart is smoothed, his left divisions and right ventricle are enlarged.
Echocardiographic diagnosis of the defect is carried out by indirect and absolute echopriminations. When scanning from high parasternal or supra-sternal access, one can directly visualize the duct or set a discharge into the pulmonary artery. Measurement of the cavities of the left atrium and left ventricle allows you to indirectly judge the size of the shunt (the larger their size, the larger the shunt). It is also possible to compare the transverse size of the left atrium with the diameter of the aorta (normally this ratio does not exceed 1.17-1.20).
Cardiac catheterization and angiocardiography are shown only in cases accompanied by a critical degree of pulmonary hypertension, to clarify its nature and the possibilities of surgical treatment.
Differential diagnosis of the open arterial duct is carried out with functional noise "top" on the vessels of the neck. The noise intensity of the "top" changes when the position of the body changes. In addition, functional noise can be heard from both sides. The diastolic component of noise in the open arterial duct often requires differential diagnosis with aortic insufficiency.
What do need to examine?
How to examine?
Treatment of open ductus arteriosus
Regardless of the diameter of the arterial duct, the fastest surgical treatment is necessary by its ligation or endovascular occlusion (with a diameter of 5-7 mm). In neonates, the closure of the duct can be achieved with indomethacin, an inhibitor of prostaglandin E, which promotes spasm of the duct and subsequent obliteration of the duct. The dose of indomethacin for intravenous administration is 0.1 mg / kg 3-4 times a day. The effect is better the younger the child (it is desirable to apply in the first 14 days of life).
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