Background: Atrial septal defect (ASD) flow can be measured indirectly by velocity-encoded cardiovascular magnetic resonance (veCMR) of the pulmonary artery and aorta (Qp/Qs). Imaging the secundum ASD en face could potentially enable direct flow measurement and, additionally, provide valuable information regarding ASD size, shape, location, and proximity to other structures.
Methods: Patients referred for possible transcatheter ASD closure underwent a comprehensive standard evaluation including transesophageal and/or intracardiac echocardiography (ICE), and invasive oximetry. CMR was performed in parallel and included direct en face veCMR after an optimal double-oblique imaging plane was determined accounting for ASD flow direction and cardiac-cycle interatrial septal motion.
We hypothesized that En face veCMR using an optimized imaging plane can accurately determine ASD flow, size, and morphology, and that it would provide information incremental to comprehensive standard evaluation.