Hi, this is Tom, and in this episode, I'm going to be going through Syncope,

and you can find notes at 0.0.5.com slash syncope, and in the 0 to Finals Pediatrics book.

And you can find flashcards and questions at members.0.0.0.com. So let's jump straight in.

Syncope is a temporary loss of consciousness caused by transient global cerebral hypopofusion,

meaning a temporary reduction of blood flow to the entire brain.

There is a rapid onset, short duration, and complete recovery.

Let's talk about vasovagal syncope.

Vesovagal syncope, which is simple fainting, is caused by a temporary imbalance in the autonomic nervous system.

In response to a strong stimulus, such as an emotional event, like having a needle phobia and seeing a needle,

or having a blood phobia and seeing blood, or to a painful stimulus, the parasympathetic nervous

system is activated and the sympathetic nervous system is reduced.

Parasympathetic signals cause a drop in the heart rate and reduced sympathetic tone causes blood vessels to relax and this leads

to a drop in blood pressure and reduced blood entering the brain and reduced perfusion of the brain

tissue. When cerebral perfusion drops below a certain threshold, the person will lose consciousness.

When you're assessing a patient who's had a syncopal episode, phasovagal syncope has three

p's, which are the features. P for posture, which is where episodes typically occur when

standing or potentially when sitting,

although sitting is less common, and they shouldn't occur while lying down.

The second P is for provoking factors where episodes often have a clear trigger,

for example seeing blood, prolonged standing or dehydration,

and the final P is for Prodrome, which is where episodes for example, seeing blood, prolonged standing or dehydration.

And the final P is for prodrome, which is where episodes are preceded by prodromal symptoms.

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