Hypoplastic Left Heart Syndrome (HLHS)

Hypoplastic Left Heart Syndrome (HLHS) is a rare but critical congenital cardiac anomaly characterized by severe underdevelopment of the left ventricle, mitral valve, aortic valve, and ascending aorta, rendering the left heart incapable of supporting systemic circulation. It accounts for 2–3% of congenital heart diseases yet remains one of the most lethal if untreated. Advances in prenatal echocardiography have enabled early diagnosis, while postnatal confirmation is achieved through echocardiography, chest X-ray, ECG, and pulse oximetry. Clinical manifestations typically appear within the first 24–48 hours of life, including cyanosis, respiratory distress, poor perfusion, and shock. The mainstay of management involves staged surgical palliation—Norwood procedure, Bidirectional Glenn, and Fontan completion—or a hybrid approach, with heart transplantation as an alternative. Perfusion strategies during these procedures are focused on maintaining systemic oxygen delivery, preventing pulmonary overcirculation, and ensuring cerebral and myocardial protection. With specialized multidisciplinary care, 10–15 year survival rates now reach 60–70%, although long-term complications such as arrhythmias, right ventricular dysfunction, and protein-losing enteropathy necessitate lifelong follow-up. HLHS continues to be one of the most challenging congenital heart diseases, requiring innovation in surgical, perfusion, and postoperative management to improve outcomes.