Near-infrared Spectroscopy (NIRS) Neurodevelopmental Outcomes
Condition: Hypoplastic Left Heart Syndrome
MeSH terms: Hypoplastic Left Heart Syndrome; Syndrome
Study type: Observational

Summary: 
      We believe that how a baby with Hypoplastic Left Heart Syndrome (HLHS)does after a major open
      heart operation, measured by things like blood pressure, oxygen saturation, heart rate and
      others, may have an impact on development. Studying how post-operative condition impacts
      outcomes may help us to protect babies better when they undergo surgery.

      This study will look at some of the long-term outcomes of children with HLHS, including both
      mental development and quality of life. We will use information from your child's medical
      record to see if early oxygen delivery has an impact on later development.
    

Detailed description: 
      Over the past twenty years, the field of congenital heart disease has been marked by globally
      improved survival after complex congenital heart surgery. These improved results are clearly
      multi-factorial and include advances in diagnostic technologies, surgical techniques,
      perfusion strategies, pharmacologic therapies and perioperative monitoring of tissue oxygen
      delivery.

      Hypoplastic left heart syndrome (HLHS) represents an extreme form of complex congenital heart
      disease in which the infant has prolonged cyanosis and a single systemic right ventricle.
      Staged palliation beginning with surgery in the neonatal period is the most common approach
      to infants with HLHS. After initial surgical palliation, infants are critically ill due to
      ischemia/reperfusion injury from cardiopulmonary bypass, coronary ischemia attributed to
      diastolic runoff, reduced total ventricular mass, continued hypoxemia during a time of
      increased metabolic demands, and finally, the inherent inefficiency of parallel circulation.
      The presence of any one of these physiologic derangements places the infant with HLHS at
      great risk for ischemia, organ dysfunction, circulatory collapse and, even, death.
      Postoperative monitoring of venous oximetry and, more recently, near infrared spectroscopy,
      have identified periods of impaired oxygen delivery and ischemia, allowed for interventions
      that enhance oxygen delivery and improved survival after cardiac surgery. Although, an
      apparent relationship exists between oxygen delivery and survival after cardiac surgery,
      little data is available on the relationship between oxygen delivery and neurodevelopmental
      outcomes (inclusive of neurocognitive and neuropsychologic outcomes).

      Preliminary data from our center has recently identified that reduced venous oximetry was
      associated with adverse neurodevelopmental outcome. These initial findings warrant further
      investigation of neurologic injury, specifically, how such morbidity relates to perioperative
      ischemia and cerebral oxygen delivery. Hence, the purpose of this study is to understand the
      relationship of perioperative tissue dysoxia and long-term neurodevelopmental morbidity in
      children subject to oxygen delivery at which neurodevelopment is compromised. Identification
      of a critical threshold that may be devastating to a child's neurodevelopment and quality of
      life would allow for early intervention, goal-directed therapy and ultimately, improve
      outcomes.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Cases:

          -  clinical diagnosis of hypoplastic left heart syndrome, status post Norwood procedure,
             bidirectional Glenn, and completion Fontan, ages 4-5 years old, English-speaking
             patient and parent, informed consent

        Controls:

        Healthy children 4-5 years old, English-speaking patient and parent, informed consent
      
Keywords: Neurodevelopmental outcomes; congenital heart disease; NIRS monitoring; hypoxia