Transposition of the great arteries
Paula Martins* and Eduardo Castela
Address: Serviço de Cardiologia Pediátrica, Hospital Pediátrico de Coimbra, Coimbra, Portugal Email: Paula Martins* - firstname.lastname@example.org; Eduardo Castela - email@example.com * Corresponding author
Published: 13 October 2008Orphanet Journal of Rare Diseases 2008, 3:27 doi:10.1186/1750-1172-3-27
Received: 19 March 2008 Accepted: 13 October 2008
This article is available from: http://www.ojrd.com/content/3/1/27 © 2008 Martins and Castela; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), whichpermits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Transposition of the great arteries (TGA), also referred to as complete transposition, is a congenital cardiac malformation characterised by atrioventricular concordance and ventriculoarterial (VA) discordance. The incidence is estimated at 1 in 3,500–5,000 livebirths, with a male-to-female ratio 1.5 to 3.2:1. In 50% of cases, the VA discordance is an isolated finding. In 10% of cases, TGA is associated with noncardiac malformations. The association with other cardiac malformations such as ventricular septal defect (VSD) and left ventricular outflow tract obstruction is frequent and dictates timing and clinical presentation, which consists of cyanosis with orwithout congestive heart failure. The onset and severity depend on anatomical and functional variants that influence the degree of mixing between the two circulations. If no obstructive lesions are present and there is a large VSD, cyanosis may go undetected and only be perceived during episodes of crying or agitation. In these cases, signs of congestive heart failure prevail. The exact aetiologyremains unknown. Some associated risk factors (gestational diabetes mellitus, maternal exposure to rodenticides and herbicides, maternal use of antiepileptic drugs) have been postulated. Mutations in growth differentiation factor-1 gene, the thyroid hormone receptor-associated protein-2 gene and the gene encoding the cryptic protein have been shown implicated in discordant VA connections, butthey explain only a small minority of TGA cases. The diagnosis is confirmed by echocardiography, which also provides the morphological details required for future surgical management. Prenatal diagnosis by foetal echocardiography is possible and desirable, as it may improve the early neonatal management and reduce morbidity and mortality. Differential diagnosis includes other causes of centralneonatal cyanosis. Palliative treatment with prostaglandin E1 and balloon atrial septostomy are usually required soon after birth. Surgical correction is performed at a later stage. Usually, the Jatene arterial switch operation is the procedure of choice. Whenever this operation is not feasible, adequate alternative surgical approach should be implemented. With the advent of newer and improved surgicaltechniques and post operative intensive care, the long-term survival is approximately 90% at 15 years of age. However, the exercise performance, cognitive function and quality of life may be impaired.
Disease name and synonyms
Transposition of the great arteries; physiologically uncorrected transposition; complete transposition; atrioven-
tricular concordance with ventriculoarterialdiscordance. The European paediatric cardiac code for this disease is 01.05.01.
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Orphanet Journal of Rare Diseases 2008, 3:27
Definition and diagnostic criteria
The transposition of the great arteries was first described by Mathew Baillie in 1797, in the second edition of the book "The Morbid Anatomy of...