Hi, this is Tom. If you're anywhere near Manchester or Norwich in January, I recommend checking

out zero to finals.com slash events for the day-long revision course where I cover all the key

facts across medicine, surgery, pediatrics, obs and guine, and psychiatry. The course dates are the 12th of January in Manchester and the 19th of

January in Norwich. So head over to 0.5.com slash events to attend the course and make sure you

absolutely smash your exams. Hello and welcome to the zero to finals podcast.

My name is Tom and in this episode I'm going to be going through atrial septal defects.

And you can find written notes on this topic at zero to finals.com slash ASD or in the zero to finals pediatrics book.

And you can find questions to train your knowledge on this content

and help you remember the information for longer at members.0 tofinals.com.

So let's get straight into it.

An atrial septal defect is a defect or a hole in the septum or the wall between the two atria.

This hole connects the right and the left atria, allowing blood to flow between them.

Let's start with the pathophysiology.

During the development of the fetus, the left and the right atria are connected. Two walls called the septum primum and the septum secondum grow across

the gap between the atria. These walls eventually fuse with the endocardial

cushion to separate the two atria. There is a small hole in the septum secondum called the

pheromon ovalee. The pheromone ovale usually closes at birth.

Defects in the septum primum or the septum secundum lead to an atrial septal defect.

An atrial septal defect leads to a shunt, with blood moving between the two atria.

Initially, higher pressure in the left atrium means that blood moves from the left atrium to the

right atrium. This is a left to right shunt. Blood continues to flow to the pulmonary vessels and the lungs to get oxygenated,

so the patient does not become cyanotic. However, increased flow to the right side of the heart

...