Causes of patent ductus arteriosus blood flow

For many premature babies, various phenomena will occur. They must be carefully cared for from the moment they are born to prevent various conditions in the child's body, such as patent ductus arteriosus. Such diseases generally occur in premature babies, and as the child grows up, the disease will gradually weaken when the child becomes an adult. However, as parents, we are worried and anxious. Let us introduce some of them to you.

1. Increased blood oxygen pressure in premature infants can cause the ductus arteriosus to contract, while prostaglandin E can cause it to dilate. The sensitivity of this reaction is related to gestational age. The incidence of patent ductus arteriosus is very high in premature infants. About half of premature infants weighing less than 1750g have patent ductus arteriosus, and the incidence in those weighing less than 1200g can reach about 80%.

The application of alveolar surfactant improves the symptoms of respiratory distress syndrome and reduces pulmonary vascular resistance. Clinical symptoms often begin to appear around 3 to 4 days after birth.

Initially, a short, soft systolic murmur can be heard at the second intercostal space on the left side of the sternum. As the left-to-right shunt increases, the peripheral vascular pulsation increases, the precordial area pulsates actively, the murmur intensifies and prolongs to the diastole. The typical continuous machine-like murmur common in older children is uncommon. The second heart sound in the pulmonary valve area is enhanced. Children who are not on a ventilator may show the three-recess sign, and abdominal examination often reveals an enlarged liver.

2. Infants and older children

(1) Mild: In infants or older children, a smaller patent ductus arteriosus may not cause any symptoms. The patient is only taken seriously when a heart murmur is accidentally discovered during a routine physical examination. Growth and development are not affected. Cardiac output is normal or slightly increased, there is no cardiomegaly or abnormal heart beats, and the 1st and 2nd heart sounds are normal. A characteristic continuous murmur can be heard at the upper left edge of the sternum or under the left clavicle. The murmur is soft at first, gradually increases in intensity, is loudest at the second heart sound, and gradually weakens during the diastole. A small patent ductus may present clinically as only a soft ejection murmur confined to systole.

In fact, most diseases like patent ductus arteriosus will occur in infancy. Parents do not need to worry too much. They can actively care for their children. If the condition is not serious, no treatment is needed and they can provide physical and mental care for their children.