So we've looked at cardiac reserve
and the baroreceptor response
and the changes that happen as Jose aged.
Now let's look at Jose at age 20, but I want
you to look specifically at the heart itself,
the valves and the arteries.
Okay, so there he is, look at his heart.
There we go, it's young, it's fit, it's healthy.
Look at the width of the walls of the ventricles.
They're even they're equal, with a
little bit bigger on the left side,
because we know that's the ventricle that
pushes blood out to the rest of the body.
Next, look at the cardiomyocytes.
Those are very specific cardiac cells.
See, they all look healthy, they're functioning,
that's what we would expect with a 20 year old.
Now, lastly, I want you to look at the arteries.
20 years old, they should be open,
clear, and able to function effectively.
So the heart of a 20 year old, we're
looking for walls that are similar sized,
a little bit bigger on the
left, because of the workload.
We're looking for valves that are open and closing
well, and we're looking for arteries that are clear.
Now let's fast forward 65 years,
let's take a look at Jose.
Remember he's led a healthy
lifestyle, he's been active.
So what we're looking at on this slide are actual
changes that are separate from a disease process.
These are the normal changes you'd
anticipate for someone as they age.
So let's look at the wall first, look
at the wall of that left ventricle.
Yeah, it is significantly thicker
than when he was 20 years of age,
and it's also thicker than the right side.
Now, that is the same remember, we expect
the left side to be a little bit bigger,
but when you see how much the left
side has enlarged since he was 20,
that is a normal sign of aging.
Next up, let's look at those specific cardiac cells.
Now we have some dark ones in there,
they're called senescent cells,
that means they're kind of aging out,
they're not functioning as effectively.
That's another difference in the amount
of cardiomyocytes that Jose has at age 85,
as compared to when he was 20.
Now finally, I want you to
take a look at the arteries.
Starting to get a little more sclerosis in there,
a little more build up than when he was 20,
but still should function fine.
Now there's something else that we
haven't really talked about yet.
I want to go right into the
heart and look at those valves.
See, by age 85, you're going to
have some sclerosis, some stiffening
of the mitral and the atrial
valves so keep that in mind.
Shouldn't be severe, but you might hear some of
that maybe when you're auscultating heart sounds.
So let's do a quick review of the changes
in Jose's heart now that he's 85 years old.
So we know that the wall of his left
ventricle is definitely thicker.
He's got some cells that are senescent, or
they're aging out so they're not as effective,
and we see a little bit of that sclerosis.
Now I want to just touch on this point here,
when we talk about the sympathetic response.
It's diminished in someone who's 85 years
old, so I'll explain more about that
but just file that away and keep that in
mind, we'll come back to it in just a moment.
Now let's take a look at Enrique.
Remember Jose's heart were changes that
happen normally with aging, minus illness
so illness was not involved.
But when we look at Enrique, he's the same
age, but he's experienced chronic illness.
Remember, he had a heart attack at age 52.
He had chronic congestive heart failure, so
he's had a different course than Jose did.
Look at his heart, what looks different to you.
Well you see, look at the valves, and we talked about
it's normal for them to get a little stiff as you age.
But if you look there, he's
likely to have leaking valves.
Now that's a problem because what
is the role and function of a valve?
Do you remember that it's supposed to keep blood
flowing through the heart in the right direction,
and not leaking back up to the other chamber.
With a leaking valve, that's going to be problematic
for someone having an efficient cardiac output
or ejection fraction.
Now look at his vessels, look at his arteries.
Wow, those are almost completely filled in.
So those are some differences that you
will see between an aging heart at 85
and an aging heart impacted by chronic illness.
Let's go back to that decreased b1 sensitivity.
Now that stands for beta adrenergic-1, so
this is a receptor that's on the heart.
Now Jose had them at age 20 and he still has
them at age 85, right, so the receptors are there
And at age 20, if the beta-1 receptors
are connected by norepinephrine
when that hits that receptor
and it causes a reaction,
you'll see that heart rate pump harder and faster.
So norepinephrine and epinephrine
are two neurotransmitters
when they connect with a beta-1 receptor on
the hear,t the heart beats faster and stronger.
Now fast forward to age 85, with the same
amount of norepinephrine and epinephrine,
the heart just doesn't respond.
Those baroreceptors have a diminished
response to the same amount.
So if I took a 20 year old heart and an 85 year
old heart and I exposed both of those hearts
to the same amount of epinephrine or
norepinephrine, the 20 year old heart would respond,
the 85 year old heart would have
a much more diminished response.
So here's a great summary slide for you.
Start on the left, and you'll see that Jose
and Enrique both started at the same place.
The next pictures show you a comparison
of the changes in normal aging,
and normal aging plus chronic illness.
So what I'd love for you to do is pause the video
and write out without looking at your notes,
write out the differences that you
remember, in Jose's heart at 85
and Enrique's heart at age 85.