00:01
Hello. Welcome to the advanced segment of
the vascular medicine lecture series. We're
going to examine a whole variety of different
diseases that affect the arteries, the veins,
the lymphatic system. And we're going to start
with arterial disease and atherosclerosis.
00:19
And as I've said in the basic series, this
is the commonest disease in the world today
that is fatal, so it's a very, very important
disease from public health and from individual
standpoint.
Let's start with a definition. Atherosclerosis
is a generalized disease. It's a broad term
for diseases in a variety of arteries. The
artery wall thickens as a result of invasion
and accumulation of white blood cells that
lead to fibrosis and inflammation, just as
if there had been an infection. Cholesterol
in the blood gets into the artery wall along
with these white cells and sets off a whole
reaction. And you can see, in the last two
pictures, a normal inside of a blood vessel
and an atherosclerotic vessel. It looks like
all kinds of hills and bumps filled with scar
tissue and cholesterol. What happens when
this develops (atherosclerosis), the artery
gradually becomes blocked. Blood flow is reduced.
We can have ischemia, or lack of blood flow,
or one can even form a blood clot and totally
obstruct the blood vessel, with the resultant
death of tissue beyond the area that has been
blocked. In the heart, blockage of a coronary
artery leads to a myocardial infarction, or
death of heart tissue (a heart attack), and
this can possibly be fatal. It is one of the
commonest events that we take care of in hospitals
around the world.
Let's talk a little bit about the epidemiology.
02:03
I've already given you some clues. This is
the number-one cause of death in the world:
atherosclerotic disease. Atherosclerotic cardiovascular
disease kills more people each year than a
whole variety of well-known other diseases,
such as Alzheimer's, accidents, and cancer.
02:25
In the United States, over 152,000 Americans
are killed by cardiovascular disease every
year, and these are individuals under age
65. In 2002, 32% of the deaths from cardiovascular
disease occurred prematurely—that is, before
age 75. And 75 is pretty close to the average
life expectancy in the United States. Indeed,
this is a major plague, and there's tremendous
efforts in the United States and throughout
the world to stem this plague.