Hi, this is Tom and in this episode I'm going to be going through to Trilogy of Fallow.

And you can find notes at zero to finals.com and in the zero to finals pediatrics book.

And you can find flashcards and questions to train your knowledge at members.0.0.0.com. And if you stick

around at the end of the episode, I'll ask you some questions to test your knowledge on what you just

heard. So let's jump straight in. Tetralogy of Fallow is a congenital condition involving

four coexisting pathologies. a ventricular septal defect,

or VSD, an overriding aorta, pulmonary valve stenosis, and right ventricular hypertrophy.

An overriding aorta refers to when the entrance to the aorta is placed further to the right

than normal, above the ventricular septal defect.

The overriding aorta means that when the right ventricle contracts and squeezes blood up,

the aorta is in the direction of travel of the blood rather than the pulmonary valve,

which causes deoxygenated blood to enter the aorta rather than the pulmonary arteries

and blood bypasses the lungs.

Pulmonary valve stenosis further encourages blood to flow through the ventricular septal defect

and into the aorta rather than through the pulmonary valve into the pulmonary vessels.

The increased strain on the right ventricle as it pumps blood against the increased

resistance of the left ventricle and the pulmonary stenosis causes the right ventricle

to become thickened and bulky, which is called right ventricular hypertrophy.

The overriding aorta and the pulmonary stenosis and bulky, which is called right ventricular hypertrophy.

The overriding aorta and the pulmonary stenosis encourage blood to be shunted from the right heart to the left bypassing the lungs. This right to left cardiac shunt means deoxygenated

blood from the systemic circulation, bypasses the child's

lungs and enters the systemic circulation again, causing cyanosis. The severity of the pulmonary

...