Transposition of the great vessels

Transposition of the great vessels
Classification and external resources
X-ray showing characteristic finding in case of Transposition of the great vessels which is called egg on side sign
ICD-10	Q20.3
ICD-9	745.1
OMIM	608808
DiseasesDB	13259
eMedicine	ped/2548
MeSH	D014188

Transposition of the great vessels (TGV) is a group of congenital heart defects (CHDs) involving an abnormal spatial arrangement of any of the primary blood vessels: superior and/or inferior vena cavae (SVC, IVC), pulmonary artery, pulmonary veins, and aorta. CHDs involving only the primary arteries (pulmonary artery and aorta) belong to a sub-group called transposition of the great arteries (TGA).

History

TGV was first described in 1797 by Matthew Baillie.

Etiologies

Preexisting diabetes mellitus of an expectant mother is a risk factor that has been described for the fetus having TGV. Additionally, the children of diabetic mothers are more likely to have aortic coarctation.^{[citation needed]}

Description

Normal heart anatomy

Subcostal echocardiographic view showing discordant ventriculoarterial connections together with the presence of parallel, rather than crossing, great arteries arising from the ventricles.

Echocardiography of a complex transposition with a ventricular septal defect and pulmonary stenosis.
Abbreviations: LV and RV=left and right ventricle, PT=pulmonary trunk, VSD=ventricular septal defect, PS=pulmonary stenosis.

Echocardiogram in transposition of the great arteries. This subcostal view shows the left ventricle giving rise to a vessel that bifurcates, which is thus identified as the pulmonary artery.
Abbreviations: RA=right atrium, RV=right ventricle, LV=left ventricle, PT=pulmonary trunk, LPA and RPA=left and right pulmonary artery.

In a normal heart, oxygen-depleted blood is pumped from the right side of the heart, through the pulmonary artery, to the lungs where it is oxygenated. The oxygen-rich red blood then returns to the left heart, via the pulmonary veins, and is pumped through the aorta to the rest of the body, including the heart muscle itself.

Transposed vessels can present a large variety of atriovenous, ventriculoarterial and/or arteriovenous discordance. The effects may range from a change in blood pressure to an interruption in circulation, depending on the nature and degree of the misplacement and which vessels are involved.

Although "transposed" literally means "swapped", many types of TGV involve vessels that are in abnormal positions, while not actually being swapped with each other. The terms TGV and TGA are most commonly used in reference to dextro-TGA (d-TGA) – in which the arteries are in swapped positions; however, both terms are also commonly used, though to a slightly lesser extent, in reference to levo-TGA (l-TGA) – in which both the arteries and the ventricles are swapped; while other defects in this category are almost never referred to by either of these terms.

Simple and complex TGV

In many cases, TGV is accompanied by other heart defects, the most common type being intracardiac shunts such as atrial septal defect (ASD) including patent foramen ovale (PFO), ventricular septal defect (VSD), and patent ductus arteriosus (PDA). Stenosis, or other defects, of valves and/or vessels may also be present.

When no other heart defects are present it is called 'simple' TGV; when other defects are present it is called 'complex' TGV.

See also

• levo-Transposition of the great arteries
• dextro-Transposition of the great arteries

External links

• Pediatric Heart Surgery
• The Congenital Heart Surgery Video Project
• Pediatric Cardiac Surgery: Repair of Transposition of the Great Arteries with Intact Ventricular Septum (TGA/IVS)
• Diagram at kumc.edu
• Transposition of the great arteries at Cardiopedia