Oral or Poster Presentation
Concurrent Session 4B - Neo Cardiovascular Science & Hemodynamics
Introduction: Poor weight gain and impaired brain growth are well documented in infants with congenital heart disease (CHD). We hypothesize that the perioperative hemodynamics of transposition of the great arteries (TGA) and single ventricle (SV) physiologies drive changes in cerebral and somatic blood flow, affecting oxygen delivery, brain and body size.
Methods: Cardiac and brain imaging of CHD infants was performed perioperatively and at 3-4 months of age using a 1.5T MRI system. Phase-contrast imaging of all major cardiac vessels and the internal carotids and basilar artery were acquired to evaluate flow distribution (QPQS) and cerebral blood flow (CBF), respectively. Three-dimensional acquisitions of the brain were obtained for volumetric analysis. Cerebral oxygen delivery (CDO2) was calculated from clinical variables and CBF. Pearson’s correlation was used to analyze relationships between hemodynamic and volumetric data at all time points.
Results: 80 infants with CHD (33 SV, 47 TGA) were scanned (80 pre-op, 78 post-op, 40 follow-up). QPQS was negatively correlated with cerebral blood flow (p < 0.0001, r = -0.41) (Figure 1) and with CDO2 (p = 0.0004, r = -0.32) (Figure 2). CDO2 was positively correlated with total brain volume (p < 0.0001, r = 0.79) (Figure 3). Pulmonary blood flow was negatively correlated with descending aorta (DAo) flow (p < 0.0001, r = -0.41) (Figure 4) while Dao flow was positively correlated with the log body weight (p = 0.004, r = 0.27) (Figure 5).
Conclusion: High QPQS negatively impacts cerebral and somatic flow. This stealing of blood flow affects CDO2, which may be a driver of poor brain growth. Furthermore, reduced somatic flow points to poor gut perfusion, thereby contributing to feeding intolerance and failure to thrive in CHD infants. A balanced circulation may be crucial in supporting the cerebral and somatic growth of this population, especially in pre-Fontan patients.