Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about

transposition of the Great Arteries.

And if you want to follow along with written notes on this topic,

you can follow along at zero tofinals.com slash transposition of the great arteries

or in the cardiiology section of the Zero

Definals Pediatrics book. So let's get straight into it. Transposition of the great arteries is a

condition where the attachments of the aorta and the pulmonary trunk to the heart are swapped,

so they're transposed with each other. This means that the right

ventricle pumps blood into the aorta and the left ventricle pumps blood into the pulmonary vessels.

In this scenario, there are two separate circulations that do not mix. One which is traveling through

the systemic system and the right side of the

heart and the other that's travelling through the pulmonary system and the left side of the heart.

Transposition of the great arteries can also be associated with a ventricular septal defect,

co-actation of the aorta and pulmonary stenosis. During pregnancy there is normal development of the fetus.

The gas and the nutrient exchange happens in the placenta.

Therefore it's not necessary for blood to flow to the lungs.

After birth the condition is immediately life-threatening

as there's no connection between the systemic circulation and the pulmonary circulation.

Therefore, the baby's blood will not be able to get oxygenated and the baby will be cyanosed.

Immediate survival of the baby depends on a shunt between the systemic circulation and the pulmonary circulation

that allows some of the blood flowing through the body to have an opportunity to travel also through the lungs to get oxygenated.

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