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hello now we're gonna talk about the
second part of cardiac arrest or
advanced life support so there are three
major cardiac arrest rhythms that we
need to be aware of ventricular
fibrillation and ventricular tachycardia
pulseless electrical activity and
asystole and we're going to talk in some
detail about each of those three
identifying some of the key similarities
and differences between them let's start
off with V fib and v-tach
so these rhythms both represent
disorganized electrical conduction which
originates in the ventricles there's a
number of different causes for
ventricular fibrillation and tachycardia
but they're most strongly associated
with primary heart disease in particular
coronary ischemia
so myocardial infarctions etc however
you can also see v-fib and v-tach in the
setting of structural heart disease
inherited channel AAPA thiis and other
clinical situations least commonly you
see v-fib and v-tach with systemic
metabolic derangements things like
electrolyte disturbances autoimmunity
toxic ingestion x' but that's really
quite rare the vast majority of these
are caused by heart attacks so here's
just a review on ventricular
fibrillation like we said in the last
lecture this is one of our two shockable
rhythms so this is randomly fluctuating
completely disorganized electrical
activity no pattern no QRS complexes the
heart is literally just going little
Ollila
in the chest it's not actually beating
meaning that there's no cardiac output
whatsoever associated with this because
the heart's not contracting this rhythm
if it's not terminated is completely
incompatible with life by contrast
here's v-tach so we mentioned this in a
prior lecture as well but v-tach is
organized it's just bizarre
so these QRS complexes are big and tall
and wide but they are organized and they
are regular now
you want to think about v-tach anytime
you see tachycardia meaning a heart rate
of greater than a hundred most commonly
greater than 150 that means your QRS
complexes are going to be coming along
more than every three millimeters on
your tracing or more than every two
millimeters in the case of a heart rate
of 150 in this case again the QRS is
wide so it's got to actually be wider
than three millimeters to be considered
v-tach but usually it's pretty obvious
these are a big wide very
strange-looking complexes and patients
in v-tach can be completely pulseless
APNIC and dead they can be completely
stable and in some cases asymptomatic or
they can be anywhere in between so the
important thing with v-tach is when we
talk about it in the context of cardiac
arrest we're talking specifically about
pulseless v-tach
meaning we don't want to treat v-tach in
a patient with a pulse especially a
stable patient the same way as we would
in a pulseless patient clearly a stable
conscious patient is going to hate if we
start CPR on them all right so single
most important intervention for v-fib
and v-tach we alluded to this before but
I want to emphasize again it is to
defibrillate now the great thing about
defibrillation is this is such an
important intervention we've started
putting defibrillators in public places
all over the world so you can now find
defibrillators in shopping malls at
sports stadiums in the back seats of
police cars all kinds of places around
the world where first responders can
access them easily and use them quickly
to save lives when needed so we're going
to go through the v-fib and v-tach
algorithm now in some detail so first
and foremost when you have a cardiac
arrest you're going to want to get help
right away and you're gonna want to
initiate CPR the highest quality CPR you
can possibly manage next priority is to
get your hands on a defibrillator as
quickly as you can and to administer a
shock for v-fib or v-tach we don't shock
other rhythms but for these rhythms
electricity is key your next maneuver is
going to
to continue CPR for five cycles or two
minutes before you perform another
rhythm check at that point if you're
still in a shockable rhythm you're going
to administer yet another shock and this
is also when you're going to give a
vasopressor drug like epinephrine after
that we're going to continue CPR for
another five cycles or two minutes where
once again we check the rhythm we
defibrillate if we're still in a
shockable rhythm and now we're going to
think about use of anti-arrhythmic drugs
in particular amiodarone
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you