Jugular Venous Pulse (JVP) Explained Clearly – Evaluation, Waveforms, Interpretation

Jugular Venous Pulse (JVP) Explained Clearly – Evaluation, Waveforms, Interpretation

August 16, 2019 57 By Bertrand Dibbert


I went into another MedCram lecture
we’re going to talk about the jugular venous pulse specifically we’re going to
talk about how to measure it what it’s good for and what the diagnostic
considerations are in terms of interpreting the waveforms so if you
take a look at the heart you’ve got the left side and the right side this is
primarily something we’re going to look at here on the right side where we put
in a central line into the internal jugular vein and down into the SVC which
is usually where the tip is now this is a hollow tube and so we’re actually able
to actually measure in a central line what’s going on in this vessel which is
a extension of the right atrium now you can also do this and we’ll talk about
this later you can also do something called a right heart catheter where we
actually float a right heart cath in here into the right atrium into the
right ventricle into the pulmonary artery and we wedge the catheter here
which as you recall after it goes to the lungs we’ll come back and actually
measure what’s going on in the left atrium so yes we are able to actually
measure what’s going on the left atrium but for right now let’s just talk about
the jugular venous pulse which is a measurement that we get in the internal
jugular vein the tip of which is in the SVC so again to review there’s two ways
that you can look at a jbp you can either look at the output from a central
line that you’ve placed or number two you can just look at the patient’s jvp
jugular venous pulse and that’s the internal jugular vein so it’s when
they’re lying down you can actually look at that area that’s just around the
sternocleidomastoid or the SCM and look at the waveform as it comes up the rest
of today’s discussion is going to be on specifically the central line wave
output cuz that that’s one way we can actually look at the waveform and see
what the waveform is doing and actually measure the waveform so
we’ll talk about that before we get to that I wanted to sort of clarify a
little bit though when we should measure the central venous pressure in a central
line and that is when someone is breathing spontaneously versus when
Solan is breathing on the ventilator so this is supposed to signify what the
intrathoracic pressure is and the intrathoracic pressure also affects the
central venous pressure because the veins are running in the thorax so when
someone is breathing spontaneously this is their intrathoracic pressure before
they take a breath in and then when they take a breath in the intrathoracic
pressure goes down and then when they breathe out it comes back up again well
this is exactly what’s going to happen to the central venous pressure and so
when you’re looking at the waveforms it’s going to be changing and so
depending on what point during the respiratory cycle you’re at you’re going
to get a different waveform and so the key point here is to always measure at
the end of exhalation this is the true point of measurements the same thing
goes for when you’re breathing on a ventilator
except however when you’re breathing on a ventilator instead of breathing in and
having a negative pressure in your chest the ventilator is pushing air into your
chest and as a result of that the intrathoracic pressure doesn’t go down
but instead it goes up the same principle applies you should always
check the central venous pressure at the end of exhalation as a result of that
you’ll see here indifferently that when you’re measuring it on someone who is
breathing spontaneously without positive pressure ventilation that measurements
always good to be at the top of the cycle on an exhalation when someone is
breathing on a ventilator it’s always good to be at the bottom but still and
exhalation so I just want to make that point for those of you who actually
measure central venous pressure I think I want to now switch to actually talking
about the actual waveforms that we see on the jugular venous waveform and the
point that I want to bring up here again is specifically where
actually we’re measuring remember the central line is going into the internal
jugular vein and it’s resting just at the tip of the SVC and where the right
atrium is anywhere along this line and so think about the things that are going
to make the pressure here go up and think about the things that are gonna
make the pressure go down okay so let’s think about things that would make the
pressure go down and that’ll make sense later so things that are gonna make the
pressure go down is gonna be if we have the atria the right atrium if it’s
relaxing if the volume is getting bigger so atrial relaxation it’s gonna make the
pressure go down okay what else could make the pressure go down well if the
tricuspid valve opens and blood is allowed to leave the right atrium and go
into the right ventricle so tricuspid valve open alright what would make the
pressure go up in this area well we know that the right atrium can contract and
so when it does contract it’s going to squish that blood into a smaller space
that’s going to make the pressure go up so atrial contraction it’s gonna make it
definitely go up and also the closure of this valve so if the opening of the
valve makes it go down the closure of this valve so tricuspid closure what’s gonna happen when this valve
closes remember that blood is always coming towards the heart and so as a
result of that if everything is in a closed system the pressure is always
going to start to rise if this valve is closed because this this chamber is
continuously filling up with blood so with that kind of knowledge actually go
over what the waveform looks like so here’s a sample of what the waveform
looks like now at first it looks kind of complicated but it actually is not and
we’ve got certain waves here and you’ll see that over and over again the first
wave I want to bring your attention to is the a wave okay that’s that first
bump the second is the C wave okay and then we have an X descent then we have a
V wave and then finally we have the wide ascent and it starts all over again and
so this area right here corresponds to this area right here and so this is one
cycle now based on what we said before
remember where we’re measuring this we’re measuring this and the superior
vena cava so what is this a wave here this a wave is simply atrial contraction and as such you’re going to see that
when the atria contract you’re going to be going through starting from from
about right here atrial systole this is where the right atrium is actually
contracting to about this point right here and then you’ve got atrial diastole
okay so when the atria when the actual muscle of the atria contract you’re
going to get this upswing in pressure at that point and it’s right about here you’ll get closure of the tricuspid
valve this is because systole occurs ventricular systole occurs okay we’ll
put that up here on trick Euler systole as a result of that when the right
ventricle contracts it’s going to close the tricuspid valve now there are some
people that believe that this bump right here is the tricuspid valve actually
closing and coming up into the right atrium causing a little bit of a bump
some people also believe that the C stands for carotid artery because the
carotid artery runs right next to the jugular venous pulse and that that
pulsation is also going to cause an increase in the pressure that is sensed
in the internal jugular vein whichever way you like to think about it this see
here is ventricular the beginning of ventricular contraction now that the
valve is closed however what occurs is the atria continues to relax as it
started here it continues to relax down because remember we’re measuring
pressure on the right side and so X specific
is atrial relaxation and that’s important to remember
now that the atria has relaxed and the X wave has as we see here the X wave is
causing a descent which means that the pressure is going down in the right
atrium there’s gonna come a point where the blood is continuing to come in to
that right atrium and it’s going to start to fill up again until it reaches
a certain point here right about the top here where the tricuspid valve opens and
as a result of that the blood then leaves the right atrium and goes into
the right ventricle and you have the wide ascent so what is the wide ascent
is blood from the atria going down into the ventricle so what is V V is
specifically filling of the right atrium I like to say V stands for veiling okay
imagine a German saying filling filling there is villain of the right atrium so
again to review a is atrial contraction then you have the C wave which is caused
by right ventricular contraction after that you have relaxation of the right
atrium which causes the ex descent then the tricuspid valve finally opens at the
top of the V wave so you have relaxation and then filling when the valve opens
again the pressure drops again and you have the right ventricle is now filling
during the Y wave and then finally you get back up to the top again and you’re
back at another a wave so to review again a is atrial contraction see is a
ventricular contraction ex descent is atrial relaxation V is atrial filling
passively and then finally Y descent is blood going from the atria down to the
ventricle on the way back up to another atrial contraction thank you for joining
us look for the second in the series where we talk about the pathology and
how this waveform can actually help us make diagnoses you