Transposition of the great arteries

The organising principle is the parallel circulation. In a normal heart the right ventricle pumps to the lungs, the left ventricle pumps to the body, and the two loops sit in series so that every drop of blood passes through both. In d-TGA the right ventricle pumps deoxygenated blood back into the aorta and around the body, while the left ventricle pumps oxygenated blood straight back to the lungs, so the two loops never connect in the intended way. The body can only receive oxygen if some blood spills between the loops at the duct, the atrial septum or a ventricular septal defect. When that mixing fails — typically as the duct closes in the first day or two of life — cyanosis deepens, lactate rises, and the infant heads towards cardiovascular collapse. ^{[2] [3]}

This page covers the full breadth of d-TGA for a fellowship candidate: the anatomy and its three subtypes, the parallel-circulation physiology, the recognition sequence from a failed hyperoxia test to a diagnostic echocardiogram, the resuscitation trio of prostaglandin E1, balloon atrial septostomy and arterial switch, the surgical legacy of the atrial-switch (Mustard and Senning) era, and the long-term neuropsychological and exercise outcomes that shape follow-up. It cross-links to the cyanotic newborn and duct-dependent congenital heart disease leaves rather than repeating the general stabilisation pathway. ^{[1] [4]}

Overview & Definition

d-Transposition of the great arteries is defined by atrioventricular concordance with ventriculoarterial discordance. The right atrium connects normally to the right ventricle, and the left atrium to the left ventricle, but the aorta arises from the morphologic right ventricle and the pulmonary artery from the morphologic left ventricle. The great vessels lie side by side rather than wrapped around each other, giving the aorta an anterior position and the pulmonary artery a posterior position — the origin of the "dextro" (d-) label, although in modern usage d- refers to the rightward position of the aortic valve relative to the pulmonary valve rather than to dextrocardia. ^{[2] [1]}

It is the most common cyanotic congenital heart lesion to present in the neonatal period, and it is the lesion most likely to cause critical illness from a closing ductus in an otherwise well term infant. Untreated, the natural history documented before the surgical era was grim: the Liebman cohort from 1969 showed that around ninety per cent of infants with complete transposition died within the first year of life, almost all from progressive hypoxaemia as mixing sites closed. ^[3] Modern repair has transformed this prognosis — survival into adulthood is now the expectation rather than the exception — but the lesion has lost none of its urgency at first presentation. ^{[4] [12]}

References12ShowHide

1. [1]Carter E; Rogers LS Transposition of the great arteries: anatomy, physiology and surgical outcomes today. Curr Opin Pediatr, 2025.PMID 40820908
2. [2]Martins P; Castela E Transposition of the great arteries. Orphanet J Rare Dis, 2008.PMID 18851735
3. [3]Liebman J; Cullum L; Belloc NB Natural history of transposition of the great arteries. Anatomy and birth and death characteristics. Circulation, 1969.PMID 4240356
4. [4]Moe TG; Bardo DME Long-term Outcomes of the Arterial Switch Operation for d-Transposition of the Great Arteries. Prog Cardiovasc Dis, 2018.PMID 30227186
5. [5]Fricke TA; Buratto E; Weintraub RG; et al Long-term outcomes of the arterial switch operation. J Thorac Cardiovasc Surg, 2022.PMID 33715839
6. [6]Williams WG; McCrindle BW; Ashburn DA; et al Outcomes of 829 neonates with complete transposition of the great arteries 12-17 years after repair. Eur J Cardiothorac Surg, 2003.PMID 12853039
7. [7]Mahle WT; Newburger JW; Matherne GP; et al Role of pulse oximetry in examining newborns for congenital heart disease: a scientific statement from the AHA and AAP. Circulation, 2009.PMID 19581492
8. [8]Ewer AK; Middleton LJ; Furmston AT; et al Pulse oximetry screening for congenital heart defects in newborn infants (PulseOx): a test accuracy study. Lancet, 2011.PMID 21820732
9. [9]de-Wahl Granelli A; Wennergren M; Sandberg K; et al Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns. BMJ, 2009.PMID 19131383
10. [10]Singh Y; Mikrou P Use of prostaglandins in duct-dependent congenital heart conditions. Arch Dis Child Educ Pract Ed, 2018.PMID 29162633
11. [11]Kasmi L; Bonnet D; Montreuil M; et al Neuropsychological and Psychiatric Outcomes in Dextro-Transposition of the Great Arteries across the Lifespan: A State-of-the-Art Review. Front Pediatr, 2017.PMID 28393063
12. [12]Devlin PJ; Jegatheeswaran A; Williams WG; et al Late Survival and Patient-Perceived Health Status of the Congenital Heart Surgeons' Society dextro-Transposition of the Great Arteries Cohort. Ann Thorac Surg, 2019.PMID 31348901