Voiceover: Let's talk about electroshock therapy.
So sometimes healthcare providers
use electrical shocks
to bring patients out of irregular heart rhythms
or irregularly fast heart rates.
And the goal is to re-establish
a normal heart rate and rhythm.
So you probably seen scenes in movies or on TV
where there is a patient in the hospital
and all of a sudden the patients eyes rollback.
And there's pandemonium in the room,
someone yells, "The patient's heart stopped."
The doctor comes running into the room,
puts two paddle in the patient's chest
and then yells "Clear!"
In this scene or scenario,
the healthcare provider is using something called
a defibrillator.
Which is a machine that shocks the heart.
So in the movies, usually the patients
knocking on death's door and has no heart beat.
But in reality, electroshock therapy is actually use
to treat a number of different
abnormal heart rates and rhythms.
For example it's use to treat atrial fibrillation,
and that's where the upper chambers
of the heart are spasming.
So atrial fibrillation sometimes this known as
Afib for short.
Another rhythm that treats is ventricular tachycardia
or Vtach, where the ventriculars are beating way too fast.
In addition to Afib and Vtach,
there are a number of other different
rates and rhythms that are
treated with shock therapy.
And we'll talk about those in a second.
So again, in the movies the patient
is usually unconscious and has no heartbeat.
But in reality, sometimes the patient's
actually awake until just before the shock.
And these patients will receive sedating medication
just before the shock, to help them fall asleep.
Because you can imagine that
getting a shock to the chest hurts.
And again in the movies, we typically see that
people are getting shocked in emergency situations,
but in reality electroshock therapy
isn't always an emergency.
There are some situations were people actually
book this shock therapy as an outpatient procedure.
So a defibrillator can shock a patient
in one of two settings.
The first is, synchronized electrical cardioversion.
In synchronized electrical cardioversion,
the defibrillator delivers a shock
in sync with the R wave on the QRS complex.
So again, the shock is delivered
and synced with the R wave.
Which is why it's called synchronized cardioversion.
Synchronized cardioversion is use
for certain arrhythmias such as
atrial fibrillation or Afib
like we talked about up here.
It's also use to treat atrial flutter
which is another type of supraventricular tachycardia
just like Afib.
It's use to treat
atrioventricular nodal reentrant tachycardia,
which is a fast heart rate cause by
an abnormal loop or circuit of electricity
going around the AV node.
And synchronized cardioversion
is used to treat someone with Vtach who has a pulse.
Now why do we care about the pulse?
In someone with Vtach,
whether or not they have a pulse
actually determines how we treat this patient.
So if the person has a pulse and is stable
meaning that they have normal blood pressure
and no chest pain
and they have a normal mental status,
they are not coming in and out of consciousness.
These people will receive medication for treatment.
And someone with Vtach with a pulse
who is unstable,
meaning that their blood pressure is low
or they are experiencing chest pain
because their heart beating so fast
they can't circulate blood well enough to the heart
to get oxygenated blood.
Or if they have an alter mental status
meaning that, they are falling in and out
of consciousness or they are confused.
These people who are unstable with a pulse in Vtach
will undergo synchronized electrical cardioversion.
Someone in Vtach without a pulse,
well they are going to go straight to defibrillation,
which is the second setting on the defibrillator.
Again so, Vtach without a pulse, defibrillation.
In defibrillation,
the electrical shock is given at any point
in the cardiac cycle.
So again it's given anytime in the cycle.
It's not in sync with the R wave
or any wave for that matter.
So sometimes defibrillation is called
asynchronous cardioversion.
A, meaning, no synchrony,
because it's not synchronizing
to any part of the cycle.
Defibrillation is use on patients who are
a seconds away from death and who have no pulse.
It's use in ventricular fibrillation,
where there is no electrical activity
in the heart.
Instead, the ventricular is just spasming
and there's no pulse.
So what's another arrhythmia where there's no pulse?
Remember sometimes Vtach doesn't have a pulse.
And in the case of Vtach,
without a pulse,
we're going to treat that with defibrillation.
Another difference in the two settings is that,
in defibrillation, a higher energy level is used.
So defibrillation is going to use a higher energy level
when delivering the shock.
So how does electroshock therapy work?
Shock therapy works by shocking
all of the hearts all at once
and depolarizing all of the heart cells
at the same time.
What happens after depolarization?
Repolarization.
And the cells go into their refractory periods.
The refractory period is sort of like the recovery time
or the window of time where the cells can't create
another action potential.
So depolarizing all of the heart cells simultaneously
briefly prevents the tissues from being
able to transmit electrical signals
because the cells are busy recharging.
They are in this refractory period.
This is the last time for the heart to reset
and allows the heart pacers to sort of
reclaim their dominant pacing role.
In short, it's kind of like
when your computer starts to act up.
What do you usually do
when your computer starts acting up?
Well usually reboot.
And so just like you reset your computer,
you're resetting the heart.
So next time you reboot your computer,
it's almost like you're putting paddles on it
and yelling "Clear!"