Research methodology of the cardiovascular system of the newborn

After the birth of a child, adaptation processes to postnatal life take place. During this period, placental blood flow ceases, the gas exchange function passes to the lungs, and fetal communication closes. Small and large circles of blood circulation becomes consistent. The resistance of the pulmonary vessels is progressively decreasing due to their opening, and in the arterial bed it is increasing. After the first breath and the beginning of pulmonary ventilation, pulmonary blood flow sharply increases, cardiac output is redistributed, and the load on the ventricles changes. The entire flow of blood from the lungs now returns to the left ventricle, significantly exceeding the volume that fell into it in utero; immediately after birth, the left ventricle increases its ejection 3-6 times more than the right ventricle. This is accompanied by an almost twofold increase in oxygen consumption by the body and a maximum cardiac output per kilogram of the mass of the child. By 6-8 weeks, the intensity of the heart is significantly reduced...