Why is the left ventricle more muscular than the right
LVH - Left Ventricular Hypertrophy Symptoms
hi guys my name is Sanjay Gupta I am a
consultant cardiologist I work in New
York in the UK and today I wanted to do
a little video on the subject of left
ventricular hypertrophy or LVH I think
it's Jaclyn one of my friends on the
internet asked me to do a video on this
because she until the G has LVH and this
is causing her a lot of concern so I
thought I'd do a quick video on LVH just
so that you understand what left
ventricular hypertrophy means and what
to do about it
okay so the good news is I have a model
of the heart okay and it's really
important to try and understand what the
heart's all about if you understand the
structure of the heart you'll understand
what we're talking about because
sometimes this jargon can be very
difficult to understand but basically
this is what the heart looks like okay
now if you dissect the heart if you cut
the heart this is what it looks like
alright so here you have the left
ventricle alright this is the main
chamber of the heart so the blood comes
in from here okay it comes in through
comes in from these little holes here it
goes in to the left atrium which is this
structure at the top then you see this
this is the mitral valve so the blood
goes through the left atrium into the
mitral valve into the left ventricle and
from the left ventricle it gets pumped
out through this valve here okay into
the aorta and this aorta is the tube the
big tube that supplies all the other
blood vessels so when you're feeling
your pulse in your wrist or in your neck
it's because that vessel that you're
feeling in your neck or in your wrist is
connected to the aorta it comes off the
aorta so the aorta is the most high
pressure chamber you know the within the
heart of the aorta and the left
ventricle that's where the pressure is
that's where the pulsatilla t is and
this this
left ventricle here this is composed of
muscle you see so that the actual
chamber itself has a muscular wall all
right and that muscular wall is supplied
by blood vessels so when you look at it
you see these small blood vessels here
the red and the blue the red are
arteries and they supply this muscle
with blood and then the veins are the
blue ones that take the blood away so
blood with fresh oxygen-rich blood comes
to the muscle the muscle takes up the
oxygen and once the oxygen is taken away
from the blood it becomes bluish because
it doesn't have much oxygen in it and
therefore it goes back to the lungs so
when we talk about people having heart
attacks what we're worried about is
these vessels getting blocked and if
this vessel gets blocked for whatever
reason that part of the heart muscle
here may not get the blood it needs and
that part of the haast muscle will
therefore die and if that dies then
that's called a heart attack okay now
what is left ventricular hypertrophy
left ventricular hypertrophy is when you
look at this muscle it looks thicker or
more muscular than normal
usually this should be no more than
about one centimeter wide okay this part
and the spot if you find that it's much
bigger than one centimeter then it is
abnormally thickened it is abnormally
muscular and therefore you have to ask
yourself why has it become more muscular
the increased muscularity or thickening
of the wall of the left ventricle is
what is called left ventricular
hypertrophy hyper meaning increased true
feeling meaning increased thickness so
left ventricular hypertrophy left
ventricle looks increasingly thick okay
so generally around about no more than
one centimeter the dimension of this bit
or the dimension of this that should be
no more than one centimeter if it's much
bigger than one centimeter that is
called left ventricular hypertrophy so
then you have to ask yourself well why
has it become more muscular why does it
look more
skilar how do you pick it up the first
way you pick it up is on the ECG because
when you do the ECG the ECG caught the
electricity has to go through a larger
pit larger amount of muscle so the
complexes of ECG will look much bigger
than normal then you have to say okay so
that's one way but that's not a very
accurate way of looking at it so the
next way you can look for it is do
something called an ultrasound an
echocardiogram where they put jelly on
the chest and have a look at this and if
on that it looks thick then you're
diagnosed with left ventricular
hypertrophy so the next question you
have to ask yourself is why is there
left ventricular hypertrophy what why
does it develop and what does it mean
what can it do to you and basically the
left ventricle gets thicker or you
develop left ventricular hypertrophy if
the left ventricle is having to work
harder if this chamber is having to pump
much harder than it needs to then being
a muscle this muscle will thicken it's a
bit like a bodybuilder if the
bodybuilder has to do more or he's doing
more he will his muscles will grow
bigger and so there are a variety of
reasons why this could get thicker the
first thing is if the pressure here in
this chamber because remember this wore
this this chamber is pumping directly
into this chamber okay now if the
pressure here is high then of course to
try and get the blood out this is going
to have to work harder and this will get
thicker so that when the pressure is
high here that is termed high blood
pressure so if you have high blood
pressure that is by far the communist
reason why people develop left
ventricular hypertrophy okay that's the
first thing the second reason people can
develop left ventricular hypertrophy is
for example this valve you see the
because the heart has to pump and then
it has to go through this valve God has
provided us with this valve because
otherwise the blood would go up in here
and as soon as the heart started
relaxing all the blood would come back
out would come back down into the heart
not go around the body so God has
provided us with this valve and what
this means is it opens allows the blood
to come out and then closest dropping
the blood from going back down into the
left ventricle but with wear and tear
and and particularly patients who are
getting older you can get a lot of wear
and tear of this valve and this can
become very narrowed and if it becomes
narrowed this is called aortic stenosis
because it's the aortic valve okay and
if it becomes de nosed here
if it becomes tight that condition is
called aortic stenosis and that would
mean that this chamber has to work much
harder to try and get the blood through
the narrowed valve into the aorta and
that condition will also cause left
ventricular hypertrophy other causes of
left ventricular hypertrophy well if
someone for example puts pinches this
area okay so you know this continues
down but if I pinch this area then of
course the pressure that has to be
generated to try and get and the blood
out is increased and that condition
where you get this pinching effect is
called coarctation of the aorta and that
is actually something that people are
often born with where this area is
narrowed and then they develop very high
blood pressures okay another way you can
develop high blood pressure is let's say
if this goes down this will go down this
this autry goes down all the way to
supply the kidneys and if you have a
narrowing in the artery that leads into
the kidneys then that is in essence the
same as being pinched but much more
downstream so what tends to happen there
is again the heart has to work much
harder to try and get the blood through
to the kidneys and therefore you develop
left ventricular hypertrophy okay so
that's what left ventricular hypertrophy
is now there are certain other
interesting things that can cause left
ventricular hypertrophy you know when we
say left ventricular hypertrophy all
we're saying is this looks thicker now
if you were born with abnormal
muscle okay so some people have a
genetic mutation where they this muscle
becomes up normally thick okay and that
condition is called hypertrophic
cardiomyopathy so where the muscle
itself is abnormal because of the
mutation and this can become very thick
significantly thick in fact and actually
if you do the blood pressure in the
patient you say oh what blood pressure
is not raised so why is the heart muscle
so thick and if it is abnormally thick
then that condition can be called
hypertrophic cardiomyopathy because it's
a disease where the heart muscle becomes
abnormally thickened hypertrophic
cardiomyopathy is very interesting
because in a small subset of patients it
can be associated with life-threatening
heart rhythm disturbances but that is
only on a small subset of patients and
often you hear about athletes who maze
you know who are playing football or
something and they often end they and
they say collapse or unfortunately drop
down dead and often on post-mortem
they're then diagnosed with this very
more thickening of the heart muscle and
if that is the case then they're
diagnosed with hypertrophic
cardiomyopathy the problem with
hypertrophic cardiomyopathy or is that
when the muscle is abnormal all sorts of
electrical abnormalities can occur
within the heart and therefore you know
some of these electrical abnormalities
can cause the heart to go very fast and
therefore the patient can collapse and
degrade into a dangerous heart rhythm so
hypertrophic cardiomyopathy is worth
bearing in mind what else there are
other conditions which can cause this to
be abnormally thick and some people can
get abnormal deposition of things in
particular people who have something
called amyloidosis people who have
myeloma or cancers sometimes they can
develop abnormal protein deposition
within the muscle walls and that can
cause the heart paradoxically to get
even weaker so though it looks more
muscular it becomes weaker and that is
called amyloid or take heart
so what is the problem with this with
with left ventricular hypertrophy let's
say someone tells you you've got a left
ventricular hypertrophy what is the
issue with it well there's clearly
something making the heart work harder
and you don't want the heart to work
harder so the left ventricular
hypertrophy is a good indicator that the
heart is working harder than normal so
you want to try and tackle whatever is
making the heart work harder than normal
so if you have high blood pressure you
want to control that blood pressure
because you don't want the heart to work
so hard why don't you want the heart to
work so hard because actually the more
muscular the heart gets the stiffer it
gets so the more muscular it gets the
stiffer it gets now what happens is the
heart is able to contract because it's
more muscular but it doesn't relax quick
enough and if it doesn't relax quick
enough then it doesn't fill without much
blood so when it compresses again or
when it contracts again less blood goes
around the body and because less blood
goes around to the body particularly the
kidneys the kidneys will sense this and
they will then get into a system where
they start absorbing more fluid trying
to restore the blood volume because the
kidneys automatically think if they're
getting less blood you're dehydrated so
they will then start absorbing fluid you
then get more fluid coming into the
heart and the heart has more work to do
with all this fluid and slowly and
gradually as time progresses the heart
can eventually start weakening so you
don't want that to happens now and
that's the first thing the other problem
with left ventricular hypertrophy is
that you know the heart is getting
thicker and thicker and thicker that the
blood supply to the heart is just coming
from these blood vessels here okay so
eventually you'll get more muscle and
the muscle will start out stripping its
blood supply and if it outstrips and
blood supply then bits of the heart will
start weakening because they're not
getting as much blood as they need to
and that is the other problem with left
ventricular hypertrophy so yes in the
early stages it tells you your heart is
working harder than normal if it is
working
our normal than you really don't want
your heart to be working harder than
normal so you should try and tackle
those things particularly blood pressure
or things like a optic stenosis if you
have a optic stenosis secondly if you do
let the heart work harder than normal
then eventually the heart rule gets
stiffer and stiffer and that will
translate into less a relaxation real
slow relaxation and if there's slow
relaxation that it fills with less blood
less blood goes out and the kidneys
start getting into this system where
they absorb more and cause all sorts of
adaptive mechanisms which can be bad for
the heart in the long run and finally if
it gets very thick it can start out
stripping its blood supply and that can
cause the heart to paradoxically weaken
because the heart muscle there's extra
heart muscle suffocates that's why yeah
you know bodybuilders as you can see you
know they they build a certain amount of
muscle and then despite everything you
can't go beyond a certain point because
you can develop a certain amount of
muscle and of course your blood vessels
develop to try and feed that muscle but
eventually if you get too big you start
out stripping the blood supply and
therefore the muscles actually
paradoxically get weak and the heart is
very similar to that the only other
thing I would say is if you have
unexplained left ventricular hypertrophy
I your blood pressure's plum normal and
there is no other explanation then it's
always worth seeing a heart specialist
to try and work out why this muscle is
more thick when you can't obviously
explain it by a mechanical thing in that
setting it may be worth having something
called an MRI scan because the MRI scan
actually looks at the muscle and
continue if there is any abnormal muscle
where and it's probably the best test we
have to understand what tissue looks
like the scan the ultrasound scan that
I'd recommended earlier that just looks
at the heart muscle it won't tell you it
won't give you too much information
about exactly what the muscle is
composed of is it abnormal protein like
this amyloid thing is it abnormal muscle
like the hypertrophic cardiomyopathy
thing or is it just normal muscle which
is thick so I hope you found this useful
my name is Sanjay Gupta and I'm gonna
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thanks alright all the best
take care
