00:01
So, as I just said diastolic murmurs
are always worth investigating.
00:05
And the two ones
we're going to look at
are aortic regurgitation
or also known as
aortic insufficiency,
and mitral stenosis.
00:12
Aortic insufficiency is a
remarkable cardiac valve problem
that has a variety of
different manifestations
with dozens of different
eponymous findings
that have been described.
00:25
I'm really gonna focus on
some of the cardinal features
of aortic regurgitation.
00:29
And let's start off with
my little acronym, LISP-T.
00:33
So, location.
00:34
The best place to listen
for aortic regurgitation
is going to be in
the tricuspid area.
00:37
It's actually somewhat between
the pulmonic and tricuspid areas.
00:41
While you're here,
this diastolic murmur.
00:44
Intensity,
this is a soft murmur.
00:47
And that's why going back to
the beginning of this lecture,
I talked about the importance
of listening deliberately
to the heart sounds,
to systole and diastole.
00:56
Many is the case where I've
been with a resident or student
who speaks volumes about the
systolic murmur that they heard,
but they completely neglect
to pick up the diastolic murmur
because they were so focused on
just hearing the systolic murmur.
01:10
So it's very important to
really focus on that period
between S2 and S1,
which is so often neglected.
01:16
So the intensity of this
murmur is going to be quiet.
01:22
Certainly the more intense it is,
the more that does correlate with
the severity of the insufficiency.
01:27
Shape and Pitch.
01:29
So, this is also a
high pitched sound.
01:32
It tends to be decrescendo,
purely decrescendo.
01:35
The classic onomatopoeia
phrasing for this one is...
01:43
So, it's starting off
relatively high,
maybe a little bit in early peak
and then going down again.
01:53
But it's going to be a lot softer.
It's very subtle,
you really have to pay
attention to find it.
01:57
The pitch is high.
01:59
And then in terms of the timing,
it tends to occur immediately
as diastole is beginning.
02:06
Because remember,
when the left ventricle contracts,
it immediately closes
and the mitral valve and
tricuspid valve, that's S1.
02:14
And then as soon as the
aortic valve closes,
which is the beginning of S2,
It's not fully closing,
what's happening is that
blood is now starting to regurgitate
back into the left ventricle.
02:26
That's the cardinal feature
that were going to deficiency
is blood going backwards.
02:30
So there's this constant
to and fro, to and fro motion
to aortic regurgitation.
02:38
It tends to not radiate
though sometimes you can hear
what's called an
Austin Flint murmur
here at the apex,
which is the sound of that
regurgitant jet of blood
hitting the left ventricular apex.
02:50
The other important features
about aortic regurgitation
are starting with
the pulse pressure.
02:56
So when the
left ventricle contracts,
that's what maintains your
systolic blood pressure.
03:01
Blood contracts,
there's this huge surge of blood
out into my extremities
where someone's got a
blood pressure cuff on
and you detect that korotkoff
knocking sound of blood
shooting past or
shooting underneath
my blood pressure cuff.
03:14
That's the systolic impulse itself.
03:16
But of course, from one
systolic impulse to the next,
it's not as if our
blood pressure collapses, right?
There's our diastolic pressure.
03:25
There's this pressure
that's maintained
during the space between
those systolic contractions,
that's your diastolic pressure.
03:33
And the thing that
maintains that pressure,
such that we aren't just
constantly losing consciousness
between every beat of our heart
is the fact that our
aorta has recoil.
03:42
When blood shoots
through the aorta, it dilates,
the valves close,
and then the aorta
has elastic recoil
that then constricts around
that huge jet of blood,
which then is maintaining
the pressure downstream
during diastole.
03:58
The trouble is that
once systole happens,
and the valve closes,
when the aortic arch recoils,
if the valve holding it together
is not functioning,
the aorta recoils and blood
is going now backwards
back into the heart.
04:15
Any valve system requires
valves that close tightly.
04:18
And if the aortic valve
is not closing tightly,
bloods going to go in both ways.
04:22
Some of it will go forward,
but a lot of it's going backward.
04:25
Because of that, we find a very
clear manifestation of that
simply by checking
somebody's blood pressure.
04:31
You'll have a high systole
and a very low diastole.
04:34
That's called your pulse pressure.
04:36
It's the difference between
your systolic blood pressure
and your diastolic blood pressure.
04:40
So let's say that our patient,
for example here
had a blood pressure of
130/50.
04:45
So, 130 being the systolic,
50 being the diastolic.
04:48
It's the difference between them
that tells us,
what the pulse pressure is?
And again,
that's that concept of
the 130 is your,
what happening in your systole
which is your
left ventricular impulse,
And the 50
is your diastolic pressure
being maintained
by that aortic recoil
with a competent aortic valve.
05:06
Somebody's pulse pressure,
if it's 80,
that difference between 130 and 50,
has a very significant
prognostic sign
suggestive of
aortic regurgitation.
05:16
And it's something which you
just wouldn't normally see
for otherwise healthy people.
05:21
Instead, I want you to focus on
the pulse pressure.
05:24
The characteristic finding of an
early diastolic decrescendo murmur.
05:29
And then one last
important feature,
you can imagine that if all
that blood is going out,
and going back in again,
your left ventricle is having
to do twice the work, right?
And only is it trying
to pump the blood
that came from
the left atrium there,
it's not going to pump the blood
that fell back in
from the aortic arch into there.
05:45
So, that blood
is working overtime,
and you're going to hear
an S3.
05:50
That third heart sound
we talked about
at the beginning of the lecture,
because it's almost as if
the heart is in failure.
05:56
It's so overloaded.
05:57
There's such increased
diastolic filling pressures,
that you're going to hear an S3.
06:02
The presence of a third
heart sound does serve as a
high likely to the ratio for the
presence of aortic insufficiency,
and the setting of
these other features.
06:11
Alright,
so that's aortic regurgitation.
06:14
one last diastolic murmur,
and this is the murmur
of mitral stenosis.
06:18
Now, fortunately, we don't see a
lot of mitral stenosis anymore,
ever since the
advent of antibiotics
that are being distributed
all over the world,
and to prevent rheumatic fever.
06:28
Because basically,
mitral stenosis is almost every time
unless it's surgical or
a few other rare birds.
06:35
It's caused by progressive closure
and stenosis of the mitral valve
in the setting of
rheumatic heart disease.
06:42
The murmur of mitral stenosis,
which I myself have only heard
a handful of times is low.
06:48
It is again diastolic.
06:51
We are going to hear it
over here at the apex
of again, location, apex intensity.
06:56
It's fairly quiet,
though depending upon
how loud it is that
that does correlate with disease.
07:01
And then the shape and the pitch.
07:04
This sound is described as a rumble
or even the growling of a dog.
07:08
So it sounds like this.
07:14
Very low in pitch, guttural,
but fairly hollow systolic.
07:19
So that's the murmur
of mitral stenosis.
07:21
And with that, I think we've
covered all the different murmurs
that we're
going to potentially hear.
07:27
And now we should move on
to start talking about
a few specific cardiac conditions
that are non-valvular in nature.