Unrepaired most severe form of hypoplastic left heart syndrome in adulthood: a case report of late diagnosis and long-term follow-up

Hypoplastic left heart syndrome (HLHS) is a rare, severe congenital heart disease (CHD) characterized by the underdevelopment of the left-sided cardiac structures, typically necessitating neonatal surgical intervention. Survival beyond infancy without surgical palliation is exceptionally uncommon.

We report the case of an 17-year-old woman with a late diagnosis of unrepaired HLHS, comprising mitral and aortic atresia, a hypoplastic ascending aorta, and a rudimentary left ventricle. Cardiac imaging provided a comprehensive anatomical assessment. Remarkably, despite the absence of surgical intervention, the patient remained clinically stable over a 10-year follow-up under exclusive medical management.

This case illustrates extraordinary natural survival in unrepaired HLHS and emphasizes the importance of specialized CHD centres in long-term management, clinical surveillance, and imaging-based evaluation of complex univentricular physiology.