Regional impairments in cerebrovascular reactivity in Fontan patients: fMRI CO2 challenge

Motivation: Despite their high risk for cerebral injuries and neurocognitive deficits, cerebrovascular health in single ventricle heart disease (SVHD) patients is understudied. Goal(s): Quantifying cerebrovascular reserve (CVR) in SVHD patients will determine the susceptibility of these patients to acute interruptions in oxygen delivery or increased metabolic demand. Approach: In this study, we used blood oxygenation level-dependent BOLD-MRI under CO2 challenge to measure CVR in patients who underwent Fontan palliation and in control subjects. Results: Regional, but not global differences, were shown in CVR between Fontan versus healthy controls. Impact: An important prognostic indicator of cerebrovascular integrity is the ability of blood vessels to dilate or constrict in response to a stimulus, measured by CVR. Therefore, quantifying CVR in SVHD patients will determine their susceptibility to increased metabolic demands.