PC-CMR permits precise discrete 3D aortic pulse wave velocity (PWV) measurements as a surrogate for changes in vascular stiffness and ventricular-vascular interaction. In this preliminary study, global PWVs are 50% higher in 3 single ventricle (SV) patients with reconstructed arch (RA) than 3 patients with native arch (NA). Furthermore, the regional distribution of PWVs in SV-RA indicates rapid deceleration (50-70%) from proximal to distal aorta that is absent in SV-NA. The abnormal shape, large caliber change, and prosthetic material of reconstructed aortas may be additional explanatory variables. Regional distribution of local PWVs could potentially predict development of abnormal ventricular-vascular interaction.