Transposition of the great arteries
Updates to Article Attributes
Transposition of the great arteries (TGA) is one of the commonest cyanotic congenital cardiac anomaliesand can account for up to 7% of all congenital cardiac anomalies 1.
Epidemiology
The estimated incidence is at ~ 1~1 in 5000 births. Transposition of the great arteries is an isolated abnormality in 90% of those affected and rarely is associated with a syndrome or an extra-cardiac malformation. It is most common in infants of diabetic mothers 1.
Pathology
Occurs as a result of ventriculo-atrial discordance with the aorta arising from the right ventricle and the pulmonary trunk from the left ventricle. It can be sub divided into two main types depending on the positional relationship of the aortic valve with the pulmonary valve.
- L type transposition of the great arteries-congenitally corrected TGA
- D type transposition of the great arteries
The article mainly focuses on the D type transposition.
An isolated TGA is incompatible with life at birth without one of the following additional anomalies (which are a common occurrence 2).
- atrial septal defect (ASD): uncommon
-
ventricular septal defect (VSD):
~ 35~35% - patent ductus arteriosus (PDA): unstable due closure following birth
- patent foramen ovale (PFO): unstable
Unstable associations account for 60 - 65 -65% of occurrences.
Associations
Approximately 90% of TGA's occur as an isolated finding and extra cardiac syndromic associations are generally rare. associations have been described with
- maternal diabetes
* - congential coronary arterial anomalies
Radiographic features
Plain film
A frontal chest radiograph classically shows cardiomegaly with a cardiac contours classically described as appearing like an egg on a string 1. There is often an apparent narrowing of the superior mediastinum as result of the aortic and pulmonary arterial configuration.
Echocardiography -: ultrasound
Allows direct visualization of anomalous anatomy with the aorta and pulmonary trunk lying in parallel with absence of crossing (best seen on the base view of the fetal heart) 4.
Contrast CT / CTA/CTA
Allows direct visualisation of anomalous great vessel anatomy. Cardiac gated cine CT can additionally assess function.
Cardiac MRI
Allows direct visualisation of anomlaous anatomy. SSFP cine sequences can additionally assess flow dynamics.
Treatment
Initially TGAs were treated with atrial switch operations, such as a Mustard repair or Senning repair, which have been superseded by arterial switch procedures 5.
-<p><strong>Transposition of the great arteries (TGA) </strong>is one of the commonest <a href="/articles/cyanotic-congenital-heart-disease">cyanotic congenital cardiac anomalies</a><a href="/articles/congenital-heart-disease"> </a>and can account for up to 7% of <a href="/articles/congenital-cardiovascular-anomalies">all congenital cardiac anomalies</a> <sup>1</sup>. </p><h4>Epidemiology</h4><p>The estimated incidence is at ~ 1 in 5000 births. Transposition of the great arteries is an isolated abnormality in 90% of those affected and rarely is associated with a syndrome or an extra-cardiac malformation. It is most common in infants of diabetic mothers <sup>1</sup>.</p><h4>Pathology</h4><p>Occurs as a result of ventriculo-atrial discordance with the aorta arising from the right ventricle and the pulmonary trunk from the left ventricle. It can be sub divided into two main types depending on the positional relationship of the aortic valve with the pulmonary valve. </p><ul>- +<p><strong>Transposition of the great arteries (TGA) </strong>is one of the commonest <a href="/articles/cyanotic-congenital-heart-disease">cyanotic congenital cardiac anomalies</a><a href="/articles/congenital-heart-disease"> </a>and can account for up to 7% of <a href="/articles/congenital-cardiovascular-anomalies">all congenital cardiac anomalies</a> <sup>1</sup>. </p><h4>Epidemiology</h4><p>The estimated incidence is at ~1 in 5000 births. Transposition of the great arteries is an isolated abnormality in 90% of those affected and rarely is associated with a syndrome or an extra-cardiac malformation. It is most common in infants of diabetic mothers <sup>1</sup>.</p><h4>Pathology</h4><p>Occurs as a result of ventriculo-atrial discordance with the aorta arising from the right ventricle and the pulmonary trunk from the left ventricle. It can be sub divided into two main types depending on the positional relationship of the aortic valve with the pulmonary valve. </p><ul>
-<a href="/articles/l-type-transposition-of-the-great-arteries">L type transposition of the great arteries</a> - <a href="/articles/congenitally-corrected-tga">congenitally corrected TGA</a>- +<a href="/articles/l-type-transposition-of-the-great-arteries">L type transposition of the great arteries</a>-<a href="/articles/congenitally-corrected-tga">congenitally corrected TGA</a>
-<a href="/articles/atrial-septal-defect-2">atrial septal defect (ASD)</a><a href="/articles/atrial-septal-defect"> </a>: uncommon </li>- +<a href="/articles/atrial-septal-defect-2">atrial septal defect (ASD)</a>: uncommon </li>
-<a href="/articles/ventricular-septal-defect-vsd">ventricular septal defect (VSD) </a>: ~ 35 % </li>- +<a href="/articles/ventricular-septal-defect-vsd">ventricular septal defect (VSD)</a>: ~35% </li>
-<a href="/articles/patent-ductus-arteriosus-pda">patent ductus arteriosus (PDA)</a> : unstable due closure following birth</li>- +<a href="/articles/patent-ductus-arteriosus-pda">patent ductus arteriosus (PDA)</a>: unstable due closure following birth</li>
-<a href="/articles/patent-foramen-ovale">patent foramen ovale (PFO)</a> : unstable </li>-</ul><p>Unstable associations account for 60 - 65 % of occurrences.</p><h5>Associations</h5><p>Approximately 90% of TGA's occur as an isolated finding and extra cardiac syndromic associations are generally rare. associations have been described with</p><ul>-<li>maternal diabetes <a href="/articles/fetal-conditions-associated-with-maternal-diabetes">*</a>-</li>- +<a href="/articles/patent-foramen-ovale">patent foramen ovale (PFO)</a>: unstable </li>
- +</ul><p>Unstable associations account for 60-65% of occurrences.</p><h5>Associations</h5><p>Approximately 90% of TGA's occur as an isolated finding and extra cardiac syndromic associations are generally rare. associations have been described with</p><ul>
- +<li>maternal diabetes</li>
-</ul><h4><strong>Radiographic features</strong></h4><h5><strong>Plain film</strong></h5><p>A frontal chest radiograph classically shows cardiomegaly with a cardiac contours classically described as appearing like an <a title="Egg on a string sign" href="/articles/egg-on-a-string-sign">egg on a string</a> <sup>1</sup>. There is often an apparent narrowing of the superior mediastinum as result of the aortic and pulmonary arterial configuration.</p><h5>-<strong>Echocardiography - ultrasound</strong> </h5><p>Allows direct visualization of anomalous anatomy with the aorta and pulmonary trunk lying in parallel with absence of crossing (best seen on the base view of the fetal heart) <sup>4</sup>. </p><h5><strong>Contrast CT / CTA</strong></h5><p>Allows direct visualisation of anomalous great vessel anatomy. Cardiac gated cine CT can additionally assess function. </p><h5>- +</ul><h4><strong>Radiographic features</strong></h4><h5><strong>Plain film</strong></h5><p>A frontal chest radiograph classically shows cardiomegaly with a cardiac contours classically described as appearing like an <a href="/articles/egg-on-a-string-sign">egg on a string</a> <sup>1</sup>. There is often an apparent narrowing of the superior mediastinum as result of the aortic and pulmonary arterial configuration.</p><h5>
- +<strong>Echocardiography: ultrasound</strong> </h5><p>Allows direct visualization of anomalous anatomy with the aorta and pulmonary trunk lying in parallel with absence of crossing (best seen on the base view of the fetal heart) <sup>4</sup>. </p><h5><strong>Contrast CT/CTA</strong></h5><p>Allows direct visualisation of anomalous great vessel anatomy. Cardiac gated cine CT can additionally assess function. </p><h5>
Unable to process the form. Check for errors and try again.