1.What is ventricular septal defect? How many types of ventricular septal defects are there? In normal people, the left and right ventricles are separated by the septum and do not communicate with each other. If the septum is not fully developed during fetal life and the hole is left behind to make the left and right ventricles communicate, it is called congenital ventricular septal defect. Generally speaking, ventricular septal defects are divided into perimembranous ventricular septal defects, subpulmonary ventricular septal defects (these two types are most common in our children) and myocardial ventricular septal defects. Among congenital heart diseases in children, ventricular septal defect, atrial septal defect, patent ductus arteriosus and pulmonary valve stenosis are the most common, commonly known as the “four giants” of congenital heart diseases. Among them, the incidence of ventricular septal defect is the highest. In fact, many complex precordial diseases are often accompanied by ventricular septal defect. 2. What are the manifestations of ventricular septal defect? Because the pressure in the left ventricle is higher than that in the right ventricle, blood is shunted from the left ventricle to the right ventricle via the septal defect, causing congestion in the child’s lungs, increased pulmonary artery pressure, increased water and blood flow in the lungs, and loss of compliance in the alveolar tissue. At the same time, the shunt between the ventricles increases the burden on the left ventricle, which affects the heart function and even develops into heart failure. The child exhibits feeding difficulties (labored, slow and incoherent feeding), excessive sweating, easy fatigue and weakness. Pneumonia and heart failure can recur, resulting in lack of growth, malnutrition and stunted growth. In severe cases, death may result. On physical examination, a systolic murmur with tremor can be heard between the third and fourth ribs at the left border of the sternum in patients with typical ventricular septal defects. In large ventricular septal defects, the sternum may appear to have a chicken chest shape, and the chest X-ray may show pulmonary congestion and left ventricular enlargement, and the electrocardiogram may show left ventricular enlargement or biventricular enlargement. How does a heart murmur occur? Generally speaking, a murmur is produced if the blood flows too fast or with too much force between the parts of the heart and the walls of the heart or large blood vessels vibrate. In addition, if the normal channels between parts of the heart become too narrow, or if there are abnormal channels in the heart, abnormal “vortices” are created as the blood flows through them, and a murmur may occur. The heart murmur is divided into physiological and pathological conditions, the heart murmur is not necessarily a precordial disease, but must be distinguished by a professional physician. 3. Do all ventricular septal defects require surgical repair? This depends on the type and size of the ventricular septal defect. If the ventricular septal defect is located in the perimembranous area and the diameter of the ventricular septal defect is small, it can wait until school age because of the possibility of natural closure, but if the septal defect does not “grow” by school age, it must be treated surgically. Children with larger diameter periventricular septal defects should receive surgery as soon as possible because of the potential for pulmonary hypertension and heart failure. In the case of subvalvular ventricular septal defects, surgery is indicated regardless of the diameter, as there is no possibility of natural closure. The ventricular septal defect sealing procedure, which has been developed in recent years in many medical centers for precordial diseases, is a useful supplement to the surgical repair of ventricular septal defects and has the advantages of less trauma, fewer complications and shorter hospital stay. It is suitable for partial perimembranous ventricular septal defects and myocardial ventricular septal defects. However, surgical repair is required for younger children and for larger diameter perimembranous ventricular septal defects, as well as for all subpulmonary ventricular septal defects. In children with large ventricular septal defects, the fractional flow is so great that pulmonary hypertension is likely to develop, and failure to undergo surgical repair in a timely manner may lead to irreversible pulmonary hypertension. What is interventional treatment for ventricular septal defect? Interventional treatment of ventricular septal defect refers to a minimally invasive method of sealing the ventricular septal defect by delivering a catheter and a metal blocker to the edge of the ventricular septal defect and releasing the blocker under the guidance of x-ray or echocardiography. 4.When is the most appropriate time to repair a ventricular septal defect? Whether it is perimembranous ventricular septal defect or subpulmonary ventricular septal defect, if the diameter is large, it will definitely cause a large amount of blood flow shunt from the left ventricle to the right ventricle, resulting in pulmonary hypertension and decreased cardiac function, and even death due to pneumonia and heart failure. For this group of children, early surgery is necessary to avoid complications and life-threatening conditions caused by ventricular septal defect and to improve the quality of life of the children. Currently, with the rapid improvement of cardiac surgery techniques and equipment, extracorporeal circulation, anesthesia, and postoperative monitoring, it is possible to repair ventricular septal defects in this group of children within one year of age. However, it is important to note that early surgery is also a prerequisite, i.e., the child must be operated on when the pneumonia is largely cured and the heart failure is largely resolved to ensure the success of the operation. For smaller diameter subpulmonary ventricular septal defects, it is recommended that repair of the ventricular septal defect be completed before the age of 4 years if there are no obvious symptoms, because as the age increases, the aortic valve will also be affected by the ventricular septal defect and become diseased, which greatly increases the risk and difficulty of surgery. For smaller diameter perimembranous ventricular septal defects, surgical or interventional treatment is required if the defect does not “grow back” by school age. In medical centers where the surgical treatment of pediatric precardiac disease is more common (e.g., Shanghai Children’s Medical Center), surgical repair of ventricular septal defects can be performed as young as one or two months (or even a few days after birth) if the condition requires it. 5.Do I need to have a cardiac catheterization before the ventricular septal defect repair surgery? In recent years, with the rapid improvement of non-invasive diagnostic techniques such as cardiac color echocardiography (cardiac color ultrasound), the diagnosis of ventricular septal defect by cardiac color ultrasound has become quite accurate, and cardiologists can make accurate diagnosis through clinical symptoms, physical symptoms, combined with chest X-ray, electrocardiogram and cardiac color ultrasound, without the need for cardiac catheterization. Considering that some children with ventricular septal defect may have vascular malformations such as unclosed arterial duct and aortic constriction, especially some children with ventricular septal defect may also have congenital airway stenosis and other malformations, in order to exclude these possibilities, further imaging examinations such as cardiac CT or cardiac MRI can be done for these children as a useful supplement to cardiac ultrasound. Only when the ventricular septal defect combined with severe pulmonary hypertension, in order to make an accurate assessment of the nature and severity of pulmonary hypertension, so as to make accurate judgment on whether the operation and prognosis of the operation can be done, it is necessary to do cardiac catheterization imaging. 6.How is the repair surgery of ventricular septal defect performed? Ventricular septal defect repair surgery is performed under general anesthesia. The skin is first cut in the middle of the patient’s chest and the sternum is separated. Extracorporeal circulation is established before the heart is opened. After the extracorporeal circulation is established, medication is injected to stop the heart from beating. The surgeon cuts through the right atrium or pulmonary artery and performs the repair of the ventricular septal defect under direct vision. There are two methods of repair: one is direct suturing; the other is patch repair. The former is indicated for smaller diameter perimembranous ventricular septal defects, while the latter is indicated for larger diameter perimembranous ventricular septal defects and all subpulmonary ventricular septal defect defects. The patch repair is performed with both synthetic polyester patches and pericardial patches taken from the child’s own heart. The right atrial or pulmonary artery incision is sutured after the ventricular septal defect is repaired. Once the heart is beating normally, the extracorporeal circulation can be removed. The sternum is closed with wire or absorbable sutures (in younger children, absorbable sutures have gradually replaced wire because of their advantages of less trauma and less impact on future life) and the skin is sutured and then transferred to the intensive care unit. The whole procedure also involves a series of steps such as anticoagulation and hypothermia. 7.What are the risks involved in ventricular septal defect repair surgery? With the rapid improvement of techniques and equipment for cardiac surgery, extracorporeal circulation technology, anesthesia technology and post-operative monitoring level, the success rate of septal defect repair surgery has been greatly improved. At present, the success rate of ventricular septal defect repair surgery is over 99% in many medical centers in China. Generally speaking, ventricular septal defect repair surgery has a good healing process and can be compared with normal children without any gap. However, there are some risks associated with ventricular septal defect repair surgery, and some complications may occur, even life-threatening. Since the heart function of children with ventricular septal defect is reduced to varying degrees compared to normal children, the surgery itself can be traumatic to the heart, and the extracorporeal circulation and general anesthesia can also have an impact on the heart function, so the recovery of heart function after ventricular septal defect repair surgery is a key issue for the success of the surgery. It is necessary to apply appropriate amount of cardiac drugs to help the early recovery of heart function after ventricular septal defect repair surgery, but if heart function cannot be recovered or even heart failure occurs after applying more cardiac drugs, it will be life-threatening. Surgical trauma can also lead to complications such as cardiac arrhythmias. Among them, complete atrioventricular block will have a greater impact on the heart function, and if it cannot be recovered, a pacemaker will be needed. In addition, extracorporeal circulation and the general process of anesthesia can also cause some damage to respiratory function, and children are prone to pulmonary complications such as pneumonia, atelectasis, pneumothorax, and pleural effusion after surgery, which can lead to respiratory failure and ventilator dependence in severe cases. In addition, because repair surgery involves a series of processes such as surgery, anesthesia, extracorporeal circulation, post-surgical monitoring and care, it may lead to endocarditis and sepsis in children with reduced resistance. Neurological complications are also possible after ventricular septal defect repair surgery, which may result in coma, convulsions, abnormal limb movements, loss of consciousness or vision, or even “vegetative state”. In short, parents must be fully prepared before their children undergo ventricular septal defect repair surgery. 8.What do I need to pay attention to after the ventricular septal defect repair surgery? Generally speaking, it takes 1 to 2 months for the child to recover after the septal defect repair surgery, and parents should pay attention to the following points during this period: 1. Pay special attention to adding less salt to the diet to avoid the accumulation of water in the body to increase the burden on the heart. 2. Keep air circulation in the room and avoid staying in crowded public places to reduce the chance of respiratory infection. Add and remove clothes in time with the warm weather and pay close attention to prevent colds. 3.Children who are recovering from heart function tend to sweat more, so they need to keep their skin clean, bathe regularly in summer, rub themselves with hot towels in winter (pay attention to keeping warm), and change their clothes and pants regularly. 4, keep the stool can be smooth, if the stool is dry, defecation difficulties, excessive force will increase the abdominal pressure, increase the burden on the heart, and may even have serious consequences. 5, regular follow-up visits to the hospital cardiology outpatient clinic, strictly follow medical advice to take medication, especially cardiac and diuretic drugs, due to their pharmacological properties, must be absolutely controlled dose, on time, according to the course of treatment to ensure the effectiveness. Before each dose of cardiac drugs, the pulse count must be measured, if the heart rate is too slow, should immediately stop taking, to prevent the occurrence of toxic effects of drugs, endangering the life of the child. 6, for infants and children, should avoid digoxin cardiac drugs and calcium powder at the same time, after the discontinuation of digoxin before taking calcium powder. 7.Attention to monitor the change of body temperature, if there is any abnormality should promptly consult a doctor. 8.Pay attention to observe whether the wound has redness, swelling, exudate and other abnormalities, if there is any abnormality, you should seek medical consultation in time. 9.Ventricular septal defect repair surgery can be performed only after 3 full if there is no abnormal fever and other conditions. 10, to ensure adequate sleep, avoid excessive crying, prohibit strenuous exercise, but do not have to lie in bed all day, advocate the combination of movement and static. Generally speaking, if there is no abnormality in the cardiology outpatient follow-up within 1 year after the ventricular septal defect repair surgery, the regular follow-up can be cancelled.