Smaller Fontan Pathway is Associated with Fontan Failure

Background The Fontan circulation is vulnerable to any flow restriction in the Fontan pathway. We measured the minimal cross-sectional area (CSA) of the Fontan circuit via cardiac magnetic resonance imaging (CMR) and assessed associations with physiologic indices and outcomes. Methods The minimum cross-sectional area (CSA) of the Fontan was calculated using the narrowest dimensions within the Fontan on a 3D gated respiratory navigated MRA sequence. CSA of the Fontan was calculated by incorporating the diameters, measured by (CMR), of the narrowest point in the Fontan pathway into the area equation for an …