Patent ductus arteriosus PDA is one of the common types of congenital heart disease in children, accounting for about 15% of all congenital heart disease cases. Passive opening of the ductus arteriosus during fetal life is an important channel of blood circulation. If it remains open and produces pathophysiologic changes, it is referred to as an unclosed ductus arteriosus. What causes ductus arteriosus? The main causes of ductus arteriosus can be divided into two categories: genetic and environmental. Any factor that affects the embryonic development of the heart during the fetal period may cause cardiac malformations. Genetic factors alone (e.g., genetic mutations, chromosomal aberrations) account for 8% of cases, environmental factors alone account for 2%, and genetic and environmental factors interact to cause 90% of cases. Environmental factors include the mother having a cold, rubella, or coxsackievirus infection during the first trimester of pregnancy; lithium intake; diabetes; alcohol abuse; maternal exposure to radiation; taking amphetamines early in pregnancy without knowing she is pregnant; and the use of certain birth control drugs, such as progesterone, for preterm abortions early in pregnancy. Symptoms and physical examination of arteriovenous ductus arteriosus 1, symptoms: related to the fractional flow and high or low pulmonary artery pressure. If the fractional flow is large, activity fatigue, shortness of breath and sweating, thin and pale, hoarse voice, repeated pneumonia and heart failure. In those with significant pulmonary hypertension, blood flow is shunted from the pulmonary artery to the aorta, and differential cyanosis occurs. 2. Physical examination: elevation of the precordial region, strong apical pulsation, and enlargement of the turbinate border to the lower left. Continuous machine-like murmur between the 2nd-3rd ribs at the left edge of the sternum, diastolic murmur in the apical region, and hyperactive second pulmonary artery sound. There is a loud continuous murmur on the lateral side, which may be transmitted to the left upper cervical dorsum, with systolic or continuous fine tremor. After the development of pulmonary hypertension, only a systolic murmur may be heard. Peripheral vascular signs may be present: femoral artery gunshot sound, watery pulse, capillary pulsation sign. How to care for the child before surgery is performed Parents should arrange a reasonable living regime for the child, both to increase exercise and improve the body’s resistance, and to rest properly to avoid overexertion. If the affected child is competent, he or she should try to live and study with normal children, but should prevent strenuous activities. At the same time, children should be educated to have confidence in treating the disease and to reduce pessimism and fear. Children with precocious heart disease are prone to respiratory infections and heart failure, so they should increase and decrease their clothing in time with the change of seasons, take them to public places as little as possible, and actively control infections when they occur. For children with cyanosis, avoid high room temperature, which may cause sweating and dehydration. Give a high protein, high calorie, vitamin-rich diet, avoid overfeeding, and keep the bowels open. Feed the infant with a dropper to reduce physical exertion. Try not to make the child cry excessively, so as not to increase the burden on the heart. It is important to note that children with precocious heart disease should receive vaccinations on time whenever possible. For parents, once a child is diagnosed with precocious heart disease, regular hospital follow-up is crucial. Echocardiography not only reflects the changes in cardiac function of precocious heart disease in a timely manner, but also allows for timely treatment timing and treatment planning, which plays a key role in the future growth and development of the child.