Now ventricular tachy. Sustained ventricular
tachycardia requires immediate intervention,
why? You are worried about v.fib and once
v.fib kicks in, you are playing with death
there and you do not want to do that. If it
is hypertension, no pulse. Stop there. Why
no pulse? If it is ventricular tachy, you
do not have effective cardiac output. You
don't have effective cardiac output because
what have you done to the diastolic interval?
Think about that. Don't you want just enough
diastole so that your left ventricle shows
up with blood. And you have ventricular tachy,
real quick? So therefore, how in the world can you possibly
fill that up with blood? You can't, it's moving too quick.
So there is no cardiac output.
What happens to pulse? It decreases. So what
is your next step of management. Cardiovert,
what does that mean? It means that you are
trying to slow things down so that you reestablish
the time that is necessary to fill up your
heart with blood to restore that hemodynamic
instability. If asymptomatic, pay attention
here now. Amiodarone, huge drug for you.
It is going to make come back for use now
and amiodarone technically fine. People say
that it is part of class III antiarrhythmics
and class III to you should mean potassium
channel blocker, but could it have sodium
channel type of activity? Could it have beta-blocker
type of activity? Could it have calcium channel
blocking activity? Sure it can. So amiodarone
is one of those drugs that kind of has all activities.
Universal, but you can use it to cardiovert
medically. Lidocaine is Ib, but failure
to convert may then require sedation and cardioversion.
So there are times when you can use medical
cardioversion, which I will pay attention
to which drugs. And then at some point you
must resort to sedation, electrical cardioversion.
It is important that you make sure that you
are able to properly sustain heart rate in
a regular fashion.
To differentiate between SVT and VT, beyond
the scope to a certain extent, but I will still
keep this in mind. Remember up until now,
we have done SVTs and we looked at four major
ones, know these four well, afib, atrial fibrillation, multifocal
atrial tachycardia, and WPW. Know these four
well, at least, and then you have VT. But what
are some other clues that you are want to
pay attention to? P waves are clearly present
preceding each QRS narrow complex. So this
would then favor what? SVT. Supraventricular
tachycardia. For example, think of atrial
fibrillation, atrial flutter, those P waves
were clearly distinct to a certain extent.
But the QRS complex was definitely there as
being a narrow complex and by distinct we
don't necessarily mean it looks like normal
sinus. The fact that maybe it was wave like,
maybe it was sawtooth, or maybe there's 3 distinct
P waves like we found in multifocal
atrial tachycarrhythmia. If the patient has
CAD stands for coronary arterial disease,
ICMP stands for ischemic cardiomyopathy, then
it is likely ventricular tachy. Is that clear?
So diseases in which the blood vessels have
been affected more likely would be VT. Keep
that in mind. Most wide complex tachy will
be VT. Most narrow complex VT, so WCT stands
for wide complex tachycardia. And for board
purposes, make sure you know that there most
likely will be ventricular tachycardias. If
the QRS complex are narrowed, think of it
is being the P waves pushing the Q waves together,
the narrow complex, and then most likely will
be SVTs. Simple clues that will help you all tremendously
and you don't want to sit there, wasting
precious time and, more importantly, feeling
AV dissociation. We talked about this where
the P wave has no correlation with the QRS
complex independent, favors ventricular tachy.