Multimodal Imaging from Fetal to Adult Life: A Comprehensive Approach to Hypoplastic Left Heart Syndrome (HLHS).

Hypoplastic Left Heart Syndrome (HLHS) accounts for 2-3% of congenital heart diseases (CHDs). HLHS is characterized by reduced systemic blood flow due to hypoplastic left ventricle (LV) and underdeveloped left-sided cardiac structures. Without a series of staged interventional treatments, HLHS is often fatal, typically within the first hours or days of life. This manuscript aims to provide a comprehensive overview of the role of echocardiography, cardiovascular magnetic resonance (CMR), and cardiac computed tomography angiography (CCTA) in the optimal management of patients with HLHS. Specifically, it explores the contributions of various non-invasive imaging modalities to the diagnosis, planning of staged palliative interventions, interstage monitoring, and long-term follow-up of HLHS. Furthermore, the advantages and limitations of each imaging technique will be highlighted to aid in clinical decision-making; however, it is important to note that, at present, no universal guidelines exist, and imaging strategies remain largely dependent on individual centre expertise and protocols.