MRI shows limited mixing between systemic and pulmonary circulations in foetal transposition of the great arteries: a potential cause of in utero pulmonary vascular disease. (16th June 2014)

• Record Type: Journal Article
• Authors: Porayette, Prashob; van Amerom, Joshua F.P.; Yoo, Shi-Joon; Jaeggi, Edgar; Macgowan, Christopher K; Seed, Mike
• Is Part Of: Cardiology in the young. Volume 25:Number 4(2015)
• Page Start: 737
• Page End: 744
• Publication Date: 2014-06-16
• Subjects: Pediatric cardiology -- Periodicals; 618.9212
• DOI: 10.1017/S1047951114000870
• Languages: English
• ISSNs: 1047-9511

Abstract

<abstract abstract-type="normal"> <title>Abstract</title> <sec id="abs1" sec-type="objectives"> <title>Objectives</title> <p>To investigate the relationship between foetal haemodynamics and postnatal clinical presentation in patients with transposition of the great arteries using phase-contrast cardiovascular magnetic resonance.</p> </sec> <sec id="abs2" sec-type="general"> <title>Background</title> <p>A severe and irreversible form of persistent pulmonary hypertension of the newborn occurs in up to 5% of patients with transposition and remains an important cause of morbidity and mortality in these infants. Restriction at the foramen ovale and ductus arteriosus has been identified as a risk factor for the development of pulmonary hypertension, and this can now be studied with magnetic resonance imaging using a new technique called metric optimised gating.</p> </sec> <sec id="abs3" sec-type="methods"> <title>Methods</title> <p>Blood flow was measured in the major vessels of four foetuses with transposition with intact ventricular septum (gestational age range: 35–38 weeks) and compared with values from 12 normal foetuses (median gestational age: 37 weeks; range: 34–40 weeks).</p> </sec> <sec id="abs4" sec-type="results"> <title>Results</title> <p>We found significantly reduced flows in the ductus arteriosus (p<0.01) and foramen ovale (p=0.03) and increased combined ventricular output (p=0.01), ascending aortic (p=0.001), descending aortic (p=0.03), umbilical vein (p=0.03), and aorto-pulmonary collateral (p<0.001) flows in foetuses with transposition compared with normals. The foetus with the lowest foramen ovale shunt and highest aorto-pulmonary collateral flow developed fatal pulmonary vascular disease.</p> </sec> <sec id="abs5" sec-type="conclusions"> <title>Conclusions</title> <p>We found limited mixing between the systemic and pulmonary circulations in a small group of late-gestation foetuses with transposition. We propose that the resulting hypoxia of the pulmonary circulation could be the driver behind increased aorto-pulmonary collateral flow and contribute to the development of pulmonary vascular disease in some foetuses with transposition.</p> </sec> </abstract>