What is a ventricular septal defect? A ventricular septal defect is a hole that exists in the ventricular septum. There are four chambers in the heart, the left and right atria in the upper left and right parts of the heart, and the left and right ventricles in the lower left and right parts of the heart. In a normal heart, the left and right chambers are separated by septal tissue. The atrial septum separates the right and left atria, and the ventricular septum separates the right and left ventricles. Normally, newborns are born with a small hole in the septum that closes on its own over the next few weeks. There is no hole in the septum, and if there is a hole, it is a septal defect. Ventricular septal defect is the most common form of congenital heart disease, with an incidence of about 0.1-0.4% in newborns and accounting for 20-30% of all congenital heart diseases. Ventricular septal defect is the most common cause of infant and child visits for congenital heart disease. What are the effects of ventricular septal defect on the child? There are different sites and sizes of ventricular septal defects. The septal tissue is made up of several different tissue components together. Some parts are made up of myocardial tissue and some parts are made up of fibrous tissue. The location and size of the septal defect can determine the effects it produces. If the ventricular septal defect is small, it is often detected during a routine physical examination due to the detection of a heart murmur. Most ventricular septal defects can close on their own, especially if they are present in the muscle. Even if it does not close on its own, if the septal defect is small, it usually does not pose a serious health problem. Of course, in the rare cases where a small ventricular septal defect is combined with some other cardiac malformation, many problems may become apparent over time. For this reason, ventricular septal defects need to be checked regularly by a cardiologist until they close on their own. If the septal defect is large, it can have a serious impact on the child in the first few months of life. Before birth, the pressure in the left and right ventricles of the child is the same. After birth, the pressure in the pulmonary vessels with the right ventricle begins to drop as breathing occurs. After 2-4 weeks, the intrapulmonary vascular pressure gradually stabilizes at a lower level, about 1/3 of the aortic pressure. During the first 1-2 weeks after birth, patients can grow and develop well even with a large ventricular septal defect. However, as the pressure in the right ventricle decreases, blood flow begins to flow from the left ventricle through the septal defect into the right ventricle, where resistance is relatively low, and congestive heart failure gradually develops. If the septum is of medium size, its prognosis is more diverse. Sometimes it can produce congestive heart failure as in large septal defects, and sometimes it simply needs to be reviewed periodically for changes as in small septal defects. Ventricular septal defects do not increase in size on their own. The ventricular septal defect gradually becomes smaller or even completely closed as the surrounding tissue obscures it. Therefore, when a ventricular septal defect is initially detected in an infant or child, immediate surgical treatment is usually not recommended, but rather clinical observation or treatment of congestive heart failure with medication to allow the septal defect to close on its own over time. What are the signs and symptoms of a ventricular septal defect? Ventricular septal defects have a very typical heart murmur, by which the doctor can determine the size and location of the ventricular septal defect. However, at birth, the murmur produced by a ventricular septal defect is not very pronounced, and this is especially true for larger ventricular septal defects. The murmur may be heard only when there is a significant flow of blood through the septal defect into the lungs. Smaller ventricular septal defects produce a louder murmur than larger ventricular septal defects. The murmur produced by a ventricular septal defect as it closes on its own is progressively louder. Think of a watering hose in a garden. If the water is allowed to flow out of the hose from the ground, the sound is minimal, but if you squeeze the outlet with your finger and make the water jet out, the sound is loud. The same is true for murmurs in ventricular septal defects. It is important to remember that a louder murmur does not mean a larger defect. With a large septal defect, the amount of blood flow through the septal defect into the lungs is excessive and congestive heart failure will occur, which will manifest itself primarily in growth and development, with no weight gain and poor development during the first few months. When the blood flow to the lungs through the septal defect is not too high, the child’s growth is usually not affected and only mild symptoms, such as shortness of breath, occur. If the child grows well during the first few months, the size of the septal defect does not cause congestive heart failure, and the child can continue to be monitored. If congestive heart failure is already present in the first few months, surgical repair is often necessary. In older children, ventricular septal defects may manifest as weakness and reduced exercise tolerance compared to children of the same age. How is a ventricular septal defect diagnosed? As mentioned earlier, ventricular septal defects produce a typical heart murmur that can be detected by physical examination. The murmur changes as the child grows, sometimes because the septal defect becomes smaller and sometimes because the blood flow shunted through the septal defect increases. Because of the increased burden on the heart to pump blood due to the ventricular septal defect, more pronounced heart beats in the chest may be seen. The child may also have shortness of breath, labored breathing, and tachycardia. An electrocardiogram can help determine if the heart is enlarged due to the septal defect, and an x-ray of the chest can also help determine the progression of congestive heart failure, the degree of enlargement of the heart, and the degree of increased blood flow to the lungs, which may increase gradually after birth. An ultrasound of the heart is also necessary. If the diagnosis of a ventricular septal defect is less clear, or may be combined with other cardiac malformations, cardiac ultrasound can confirm the diagnosis. In moderate or large ventricular septal defects, ultrasound must be performed in order to give the cardiologist definitive information about the intracardiac malformation. Small ventricular septal defects, on the other hand, can be diagnosed without repeated cardiac ultrasound because they have a tendency to close on their own. In rare cases, cardiac catheterization is also required. Cardiac catheterization provides information about how much blood flow is shunted through the ventricular septal defect into the lungs and can help determine whether a patient needs surgery. How is a ventricular septal defect treated? Smaller ventricular septal defects, especially in older children, may be examined once every 2-3 years, while larger ventricular septal defects, especially in infants, may be examined on a weekly basis. If there is a combination of heart failure, oral medications are also prescribed, usually diuretics to remove excess fluid from the body and reduce the burden on the heart, digoxin to increase the contraction of the heart, and sometimes medications to lower blood pressure can also help reduce the burden on the heart. In children who have difficulty eating and are not growing well, they are fed with a high-energy nutritional formula or even given food directly into the stomach through a nasogastric tube to promote growth and development. The goal is to control the degree of heart failure so that the child gains time to grow and develop. As the child grows, the ventricular septal defect may become smaller and its effects on the body may diminish, and the ventricular septal defect may eventually heal. Surgical repair of a ventricular septal defect is required if the symptoms produced by the defect are difficult to control with medication or if there is evidence of an excessive burden on the heart. The success rate for repair of a simple ventricular septal defect is over 99%. Interventional approaches to treating ventricular septal defects are still in the clinical research phase, and this new approach has not yet gained widespread acceptance. What are the long-term effects of a ventricular septal defect? If smaller ventricular septal defects do not close on their own, they usually pose little or no problem. There may be only a slight increase in the risk of infective endocarditis, especially if oral therapy is available. If there is a septal defect, the doctor will usually give antibiotics once before oral treatment to reduce the risk of infective endocarditis. If the ventricular septal defect has closed, this is not a problem at all. If the larger ventricular septal defect is not closed, it may pose two problems: i. The heart failure caused by the ventricular septal defect can lead to growth retardation in the child and can also affect the development of the brain. Therefore, nutritional support during this period is quite critical. Moreover, children with ventricular septal defect will often develop lung infections, which are more severe and frequent than in other children. If the ventricular septal defect is not closed, the blood flow in the pulmonary artery continues to increase, and over the years, the walls of the pulmonary vessels thicken as a result, resulting in a severe increase in pulmonary artery pressure and the development of “Eisenmenger’s syndrome” or pulmonary vascular disease. When the pulmonary artery pressure exceeds the aortic pressure, the unoxygenated blood in the pulmonary artery flows through the ventricular septal defect into the aorta and mixes with the oxygenated blood therein, and this mixing results in cyanosis. The early increase in pulmonary artery pressure is reversible, but gradually progresses to an irreversible lesion. In adults, the only treatment option for this group of patients is a combined heart-lung transplant. Fortunately, “Eisenmenger’s syndrome” is a rare occurrence. With timely detection and proper treatment, patients with ventricular septal defects can lead a happy life like any other.