In Vivo and In Vitro Approaches to Modeling Hypoplastic Left Heart Syndrome

Purpose of Review: Hypoplastic left heart syndrome (HLHS) is a critical congenital heart defect characterized by the underdevelopment of left-sided heart structures, leading to significant circulatory challenges, and necessitating multiple surgeries for survival. Despite advancements in surgical interventions, long-term outcomes often involve heart failure, highlighting the need for a deeper understanding of HLHS pathogenesis. Current in vivo and in vitro models aim to recapitulate HLHS anatomy and physiology, yet they face limitations in accuracy and complexity. Recent Findings: In vivo models, including those in chick, lamb, and mouse, provide insights into hemodynamic and genetic factors influencing HLHS. In vitro models using human induced pluripotent stem cells offer valuable platforms for studying genetic mutations and cellular mechanisms. Summary: This review evaluates these models' utility and limitations, and proposes future directions for developing more sophisticated models to enhance our understanding and treatment of HLHS.