Yes, hello! I’m Joseph Alpert with “Introduction
to Cardiology”. Today, we are going to
do Part 6 which is the second in the series
of Cardiovascular Pharmacology.
The most important thing to remember in Cardiovascular
Pharmacology is what disease are we dealing
with or rather what diseases are we dealing
Well, there’s one disease that’s exceedingly
common in the world. It’s relatively rare
in countries without very much economic power,
but in countries with considerable economic
growth and development, this disease becomes
So, what is the leading cause of death in
the world? Is it Alzheimer’s disease? Is
it accidents? Is it cancer? Well, let’s
think about that for a moment. In fact, it’s
none of the above. Many millions of people
are affected by this disease. This disease
is atherosclerosis - hardening of the arteries
in the layman’s term in English and it causes
more deaths than all of the previously mentioned
diseases. Alzheimer’s, accidents and cancer
put together actually do not equal the number
of people who die from the complications of
In fact, in the United States, one in three
deaths is the result of atherosclerotic disease
and there’s one death every 30 seconds in
the US from this disease.
Now, it affects different organs, it affects
most commonly the heart causing heart attacks
or myocardial infarctions. It can cause sudden
death and frighteningly, the first manifestation
of atherosclerosis of the coronary disease
is often sudden death.
In cardiology, we refer to it as coronary
artery disease because those are the arteries
affected that lead to myocardial infarction
or heart attack and the abbreviation CAD for
“Coronary Artery Disease” is frequently
used. It is the number one killer in the United
States and it is now the number one killer
in the world as many countries have moved
from lower economic development phases into
more western and highly technical developments.
The disease comes along with the western lifestyle.
And of course, here, again, the point is made
that it is the commonest cause for death in
the United States, in Western Europe and now,
in many parts of Asia, it has also become
the commonest cause of death.
So, what is the cause of atherosclerosis?
Well, there are multiple factors. I think
most people have heard from the media that
it’s a variety of things. Cigarette smoking,
high blood pressure, a whole variety of factors
play a role in the development of hardening
of the arteries, but the most important element
is elevated blood cholesterol.
When we examine blood cholesterol in natives,
for example, in the highlands of New Guinea,
who are healthy and eating well, it is one
third the value that you see in Western Europe
and the United States.
In fact, in the United States, we estimate
that approximately 50% of the population has
a cholesterol value that is too high. And,
it is this high level of cholesterol often
combined with other factors such as smoking
or high blood pressure or diabetes that leads
to atherosclerosis. The disease unfortunately
starts in childhood and then can rapidly progress
depending upon the presence of other risk
factors and usually, affects people in the
middle of their life at ta time when they
are most productive. And as I have said before,
the most frightening and disconcerting symptom
is sudden death, which in 50% of people, is
the first manifestation of coronary disease.
We are going to have a whole lecture on coronary
disease later in this series, but it’s important,
in terms of understanding what drugs we have
and what drugs have been developed, to understand
what disease we are frequently dealing with.
Well, let’s talk a little bit about elevated
lipids or elevated fats in the blood. The
medical term is hyperlipidemia. “Hyper”
in Greek means “large” or “increased”
and “lipidemia” means “lipid” or “fats
in the blood stream”. This is high levels
of variety of fats in the blood stream.
When we talk about lipids on a clinical basis,
we usually refer to four commonly measured
lipids. Now, there are a number of others that
are particularly useful in various research
projects. But at the moment, the ones we concentrate
on are total blood cholesterol, LDL cholesterol -
so called low density lipoprotein cholesterol,
HDL cholesterol - also called high density
lipoprotein cholesterol, and triglycerides.
Let’s talk just a little bit about them
for a moment because then you can see, we are
going to be talking about drugs for controlling
hyperlipidemia to prevent… or heart disease
in the first place, in people who are at high
risk or in fact, to treat them once they have
developed heart disease in an attempt to prevent
the disease from progressing.
So, the point about high fats that’s important
to remember is that there are other components
in the blood stream beside those, but in the
daily clinical activities, we measure the
four that were just mentioned. Again, these
are the lipids that lead to atherosclerosis
and atherosclerosis can lead to myocardial
infarction or heart attack or stroke or kidney
failure or even heart failure.
So, you see the… all of these processes
start with levels of cholesterol and triglycerides,
but mostly, cholesterol in the blood that
are too high. In fact, the higher your blood
cholesterol, the greater your risk of having
a myocardial infarction or even dying of a…
a heart attack or the complications of a heart
attack. You will notice from this curve, as
we look on the bottom - as total blood cholesterol
rises, moving from left to right, you will
see that there is an increase in the manifestations
of coronary disease including heart attacks,
strokes and death.
So, let’s about each of these individual
forms of cholesterol and then we are going
to talk about the therapy which is now available