What Is Hypoplastic Left Heart Syndrome? Hypoplastic Left Heart Syndrome (HLHS) is a serious congenital heart disease caused by underdevelopment of the structures on the left side of the baby's heart in the womb. In a normal heart, the left ventricle pumps oxygenated blood coming from the lungs to the whole body through the aorta. In babies with HLHS, the left ventricle may be very small. The mitral valve, the aortic valve, and the beginning part of the aorta may also be underdeveloped. For this reason, the heart cannot provide the blood circulation the body needs in the normal way. HLHS is a critical heart disease that requires urgent medical intervention in the first days after birth. Why Does Hypoplastic Left Heart Syndrome Occur? HLHS occurs during the baby's heart development in the womb. The exact cause of the disease is unknown in most cases. It may be associated with some genetic changes and family predisposition. HLHS may be seen together with other congenital heart anomalies. What Are the Symptoms of HLHS in Newborns? Babies with HLHS may look normal at first right after birth. However, in the hours or days after birth, when the vessel connection called the ductus arteriosus begins to close, serious circulatory impairment may develop. The main symptoms are as follows: - Rapid breathing and difficulty breathing - Bluish discoloration or paleness of the lips and skin - Feeding difficulty - Excessive sleepiness and weakness - Cold hands and feet - Weak pulse - Decreased urine output - Circulatory failure and shock in severe cases These symptoms require urgent evaluation in newborns. How Is Hypoplastic Left Heart Syndrome Diagnosed? HLHS can be diagnosed in some babies during pregnancy by fetal echocardiography. Prenatal diagnosis helps in planning for the baby to be born at a center with suitable equipment. The main diagnostic methods used after birth are as follows: 1. Echocardiography (ECHO) It is the main diagnostic method that evaluates the development of the structures on the left side of the heart, the valves, and blood flow. 2. Oxygen Saturation Measurement The oxygen level in the baby's blood is checked. 3. Electrocardiography (ECG) The electrical activity and rhythm of the heart are evaluated. 4. Chest X-Ray It provides helpful information about heart size and lung circulation. 5. Advanced Imaging and Catheterization It may be used when necessary for detailed evaluation of heart anatomy and vascular structures. How Is the Initial Treatment Done in Babies Diagnosed with HLHS? Newborns diagnosed with Hypoplastic Left Heart Syndrome need to be evaluated urgently by pediatric cardiology and neonatal intensive care teams. The aim of the initial treatment is to ensure adequate blood flow to the body and to prepare the baby for the next stage of treatment. Prostaglandin E1 Treatment It is given to keep the vessel connection called the ductus arteriosus open. This connection is vital for maintaining body circulation in newborns with HLHS. Intensive Care Support The baby's breathing, blood pressure, oxygen level, and blood supply to the organs are closely monitored. Breathing support, medication treatment, and feeding support are provided when necessary. Is Surgery Necessary in Hypoplastic Left Heart Syndrome? HLHS is not a disease that can resolve on its own. Treatment options include staged surgical procedures, heart transplantation in suitable patients, and hybrid procedures in some cases. A treatment plan is created by the specialist team in line with the baby's anatomical features, general health condition, and the family's preferences. In surgical treatment, the aim is to use the right ventricle of the heart so that it provides body circulation and to gradually rearrange the lung blood flow. The Three-Stage Heart Operation Used in HLHS Treatment The surgical approach commonly used in Hypoplastic Left Heart Syndrome is a three-stage heart operation. Stage 1: Norwood Operation The Norwood operation is generally performed in the first days or weeks after birth. During this operation: - The small aorta is reconstructed. - Blood flow from the right ventricle to the body is established. - A suitable connection is created so that blood reaches the lungs. The Norwood operation is one of the complex heart surgeries performed in the newborn period. In some babies, a hybrid method may be preferred instead of surgery at the first stage. Stage 2: Glenn Operation The Glenn operation is generally performed when the baby is 3–6 months old. The timing may vary according to the child's development and clinical condition. At this stage, the oxygen-poor blood coming from the upper part of the body is directed straight to the pulmonary arteries without passing through the heart. In this way, the aim is to reduce the workload on the right ventricle. Stage 3: Fontan Operation The Fontan operation is generally planned at around 2–4 years of age. However, the appropriate timing may differ for each child. In this procedure, the venous blood coming from the lower part of the body is also directed to the lung vessels. In this way, most of the oxygen-poor blood returning from the body reaches the lungs without passing through the heart. After the Fontan operation, the circulatory system has been rearranged. However, the heart's anatomy does not become completely normal. Are HLHS Operations Risky? The operations performed in Hypoplastic Left Heart Syndrome are among the most complex operations in pediatric heart surgery. Surgical risks vary according to the baby's weight, heart anatomy, organ functions, and accompanying health problems. Possible complications include: - Bleeding and infection - Heart rhythm disorders - Impairment of heart function - Circulation and oxygenation problems - Clot formation - The need for additional intervention or surgery Children who receive staged surgical treatment need to be followed closely after each operation. The Recovery Process After Surgery After HLHS operations, babies and children are followed in the pediatric heart surgery intensive care unit. During the recovery process: - Heart and circulatory functions are monitored. - Oxygen level and breathing are evaluated. - Feeding and weight gain are followed. - Heart rhythm is checked. - Necessary medication treatments are arranged. - Planning is made for the next surgical stage. Close follow-up is especially important in the period between the Norwood and Glenn operations. Can Children Live Normally After HLHS Surgery? After staged surgical treatment, many children can grow, continue their education, and take part in daily activities. However, HLHS is not a disease that is completely eliminated by operations. In children with Fontan circulation, complications such as heart rhythm disorders, reduced exercise capacity, liver problems, and deterioration of heart function may develop in later years. In some patients, a heart transplant may be needed in later periods. For this reason, children with HLHS need to be followed for life by cardiology teams experienced in congenital heart diseases. Why Is Early Diagnosis Vital? HLHS is a critical disease that can cause serious circulatory failure in the first days after birth. Diagnosis during pregnancy allows the birth to be planned at a center with pediatric cardiology, pediatric heart surgery, and neonatal intensive care facilities. Early diagnosis and treatment started on time can increase the baby's chance of survival and help prevent serious organ damage. Remember: Hypoplastic Left Heart Syndrome is a serious congenital heart disease that requires urgent and specialized treatment. Early diagnosis, staged surgical treatment, and regular lifelong follow-up are of great importance in increasing children's life expectancy and quality of life.