About HLHS

Hypoplastic left heart syndrome (HLHS) is the most complex and highest-risk congenital heart defect, but is a rare condition, and even the largest children’s hospitals have only a small number of HLHS patients. This heart defect is fatal without early intervention.

A small percentage of children with HLHS receive heart transplants, while the large majority receive a series of three cardiac surgeries to survive:

  • Stage I (Norwood) procedure occurs within a few days of birth

  • Stage II (Glenn) typically occurs within 4-6 months of birth

  • Stage III (Fontan) procedure occurs between 2-4 years of age

Some children do not survive to undergo any surgical procedure. HLHS patients that do survive commonly need home tube feedings, and have frequent outpatient office visits and unplanned hospital readmissions. 



Our existing quality improvement project is working to improve survival and quality of life of infants with Hypoplastic Left Heart Syndrome during the "interstage" period between discharge from their initial open heart surgery- Stage I Norwood- and admission for a Stage II Glenn procedure.

NPC-QIC enrolls over 95% of patients with HLHS cared for during the interstage period across participating care centers. Research studies published by NPC-QIC to date have identified “best nutritional practices”, and developed a nutritional algorithm that was rapidly implemented across NPC-QIC and led to significantly improved growth of HLHS infants

Significant Improvements

NPCQIC has achieved significant improvements in outcomes for infants with HLHS during the interstage. To accomplish this, NPC-QIC developed and supported a robust national registry comprised of clinical process and outcome data on the care of infants in the “interstage” period. Using this data, The Collaborative has engaged pediatric cardiologists, nurses, dieticians, other care providers and parents from cardiology programs across the nation and implemented quality improvement strategies to standardize and improve care for these infants.  Our accomplishments to date include:

  • Identifying a growth bundle of several factors that contribute to improved growth during the interstage – a time period of particularly poor growth for these infants.Seventy seven percent of the babies in the registry now have adequate growth.

  • Improving discharge and home monitoring practices that have resulted in a reduction of interstage mortality by 46% for infants cared for by teams participating in the Collaborative.

  • Creation of an interstage change package that includes information on the many practices that have been implemented by NPC-QIC sites and the methods to initiate these practices.

While these efforts in the “interstage” continue, the Collaborative is now expanding its focus on care and outcomes of these infants from diagnosis through the child’s first year of life.