Name: Atrial fibrillation (Afib) | Circulatory System and Disease | NCLEX-RN | Khan Academy
Uploaded: 2017-10-14T14:28:36.000Z
Duration: 3 min 58 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

- Atrial fibrillation
is a heart arrhythmia

It's one of the
supraventricular tachycardias.

In a normal heart, electrical wavelengths

are conducted from the
SA node to the AB node

And since you have
organized conduction going

from the SA node to the AV
node you're going to get

concentric or unified
contraction of the atrial tissue.

However, in AFib
wavelengths are in disarray.

So notice how they're all
erratic and going everywhere.

you're not going to
have unified contraction

of the atria, instead with
these erratic wavelengths

It actually kinds of
looks like there's a bag

of worms in the atria and
they're all moving around,

Also the wavelengths are
doing their own things,

so they're going to be signaling
the AV node erratically

and this is going to lead
to an irregular rhythm,

the R-R intervals is
different with each beat.

In a normal heart it's the
evenly spaced R-R intervals.

With AFib you have
different distances between

Also in AFib there are no
distinct P-waves on EKG.

Instead you have the coarse
squiggly lines running through.

But there are no distinct
P-waves, that's because

unified concentric
contraction of the atria,

so you have these coarse
squiggly lines instead

What are the risk factors
for atrial fibrillation?

Well anyone that had
diseased atrial tissue

And how does atrial
tissue become diseased?

Well, with old age, so
the skin in your body

tends to get old with age,
so does your atrial tissue.

Also anything that causes
the tissue of the atria

become inflamed can cause
atrial fibrillation.

So imagine if you just had
a recent heart procedure

that causes inflammation,
that will increase

your risk for atrial
fibrillation and anything

This includes years of high blood pressure

and also certain types
of valve disease like

mitral stenosis, certain
types of lung dissease

and previously having AFib
can enlarge your atria.

It's also worth mentioning
that people who have AFib

are at an increased
risk for having strokes.

Now why are these people at
a higher risk for stroke?

When the atria is
spasming blood is going to

blood then pools in the
atria and it doesn't move.

And what happens to
blood that doesn't move?

Now imagine, so I'm drawing
a big clot right here,

and imagine if this
clot escaped the atrium,

it could go to other
organs, including the brain.

and if a clot goes to a
blood vessel that supplies

Therefore, people who
have had AFib are usually

put on blood thinners
which will help prevent

clot formation and thereby reduce the risk

Subtitles ListPlay Video

Atrial fibrillation (Afib) | Circulatory System and Disease | NCLEX-RN | Khan Academy

sort

rhythm

specifically

typically