title: Maternal hyperoxygenation and foetal cardiac MRI in the assessment of the borderline left ventricle.
abstract: Using phase-contrast MRI in a foetus with borderline left ventricular hypoplasia at 37 weeks' gestation we showed an increase in pulmonary blood flow during maternal hyperoxygenation. The associated increase in venous return to the left atrium, however, resulted in reversal of the atrial shunt, with no improvement in left ventricular output. The child initially underwent single ventricle palliation with a neonatal hybrid procedure, but following postnatal growth of the left ventricle tolerated conversion to a biventricular circulation at 5 months of age. We conclude that when there is significant restriction of filling or outflow obstruction across the left heart, neither prenatal nor postnatal acute pulmonary vasodilation can augment left ventricular output enough to support a biventricular circulation. Chronic pulmonary vasodilation may stimulate the growth of the left-sided structures allowing biventricular repair, raising the intriguing question of whether chronic maternal oxygen therapy might obviate the need for neonatal single ventricle pallation in the setting of borderline left ventricular hypoplasia.
authors.affiliation: 1Department of Pediatrics,Labatt Family Heart Center,Division of Cardiology,University of Toronto School of Medicine,Toronto,Ontario,Canada.
authors.forename: Sharon
authors.initials: S
authors.lastname: Borik
authors.affiliation: 2Department of Physiology and Experimental Medicine,The Hospital for Sick Children,University of Toronto School of Medicine,Toronto,Ontario,Canada.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Macgowan
authors.affiliation: 1Department of Pediatrics,Labatt Family Heart Center,Division of Cardiology,University of Toronto School of Medicine,Toronto,Ontario,Canada.
authors.forename: Mike
authors.initials: M
authors.lastname: Seed
mesh_terms: D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000002:abnormalities*; D006352:Heart Ventricles / Q000002:abnormalities*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000175:diagnosis* / Q000601:surgery*; D007223:Infant; D008279:Magnetic Resonance Imaging; D011651:Pulmonary Artery / Q000601:surgery*; D015607:Stents
keywords: Foetal MRI; hybrid procedure; hypoplastic left heart syndrome