This proposal presents a proof of concept for the use of pulmonary flow restrictors (PFRs) based on MVP™-devices, drawing from clinical experience, and explores their potential role in the management of newborns with hypoplastic left heart syndrome (HLHS), other complex left heart lesions, and infants with end-stage dilated cardiomyopathy (DCM). At this early stage of age, manually adjusted PFRs can be tailored to patient’s size and hemodynamic needs. Although currently used off-label, PFRs have substantial potential to improve outcomes in these vulnerable patient populations. When integrated into a holistic treatment strategy, they represent a promising advancement in care. There is significant potential to reduce mortality and improve the quality of life for neonates with HLHS and variants, as well as to support age-dependent functional regeneration in DCM, all while avoiding the need for advanced surgical procedures, including general anesthesia. The main barrier to broader adoption is the limited availability of appropriately sized MVP devices. However, with ongoing patient-centered knowledge sharing and refinement of transcatheter techniques, there is reason for optimism that PFRs, tailored for individual patients, could provide significant benefits to thousands of infants with congenital heart disease and DCM worldwide.© 2025. The Author(s).